DESC:TECHNICAL FIELD OF THE INVENTION

[0001] The present disclosure/invention relates generally to receivers and more particularly, to a front end receiver of Target detect and identify System (TDIS).
BACKGROUND OF THE INVENTION

[0002] Generally, a receiver is well known in the art which is used to receive the signals and determine properties of the object(s) i.e., may be about the object's location and speed, etc. Further, a receiver of Target detect and identify systems (TDIS) is generally used to detect the radio emissions of radar systems. Their primary purpose is to issue a warning when a threat radar signal is detected.
[0003] Normally, the TDIS uses Ultra- wideband sensitive receivers to collect radar waveforms from the RF environment. It then detects radar signals in the presence of receiver noise. The TDIS may have signal processors which extract parameter from the detected radar signals and use them to identify specific radar systems and determine their properties. The challenge for a TDIS receiver is to do all this quickly in a dense RF environment, number of radar pulses per second radiating in multiple frequency bands.
[0004] One of the prior art discloses “LOW COST MILLIMETER WAVE RECEIVER AND METHOD FOR OPERATING SAME”. This prior art method comprises receiving the first signal, converting the first signal of the bandwidth into an intermediate frequency band, splitting the converted first signal into N of intermediate signals each having a bandwidth less than the digital processor bandwidth, wherein N is an integer greater than one, down converting each of the N intermediate signals to the second frequency band, processing the down converted plurality of signals with the digital processor to generate N processed signals, up converting each of the N processed signals to the intermediate frequency band, converting the up converted signals to the third frequency band, and transmitting the converted signals.
[0005] Another prior art discloses a “Front-End Module of 18–40 GHz Ultra-Wideband Receiver for Target detect and identify System”. In this prior art, an approach for the design and satisfy the requirements of the fabrication of a small, lightweight, reliable, and stable ultra-wideband receiver for millimeter-wave bands is disclosed. This prior art uses the chip-and-wire process for the assembly and operation of a bare MMIC device. In order to compensate for the mismatch between the components used in the receiver, an amplifier, mixer, multiplier, and filter suitable for wideband frequency characteristics were designed and applied to the receiver. To improve the low frequency and narrow bandwidth of existing products, mathematical modelling of the wideband receiver is performed and based on this spurious signal generated from complex local oscillation signals were designed so as not to affect the RF path. In the wideband receiver, the gain is between 22.2 dB and 28.5 dB at Band A (input frequency, 18–26 GHz) with a flatness of approximately 6.3 dB, while the gain is between 21.9 dB and 26.0 dB at Band B (input frequency, 26–40 GHz) with a flatness of approximately 4.1dB. The measured value of the noise figure at B and A is 7.92 dB and the maximum value of noise figure, measured at B and B is 8.58 dB. The leakage signal of the local oscillator (LO) is –97.3 dBm and –90 dBm at the 33 GHz and 44 GHz path, respectively. The measurement is made at the 15 GHz IF output of band A (LO, 33 GHz) and the suppression characteristic obtained through the measurement is approximately 30 dBc.
[0006] Further prior art discloses a “2-18 GHz ESM Receiver Front-End”. This prior art describes the design and evaluation of dual channel 2-18 GHz front-end module for Electronic Support Measures (ESM) applications. The module converts signals anywhere in the 2-18 GHz frequency band to an IF suitable for digitization. It includes limiting, filtering and amplification. The frequency conversion is realized by an intermediate transition to a frequency around 22-23 GHz. The module contains 12 GaAs MMICs including 5 different designs 4 of which are full custom parts. It exhibits a gain of 10dB, a noise figure of around 7dB and a typical output 1dB compression point of -10dBm.
[0007] In the present scenario, the radars are capable of radiating signals in multiple frequency bands and also rapidly switch operating frequency. Thus, the front-end receivers of Target detect and identify System (TDIS), require ultra-wideband operation and fast switching local oscillators for identifying radars operating in multiple frequency bands.
[0008] Therefore, there is a need in the art with a multi-channel multi-octave front end receiver to solve the above-mentioned limitations.
SUMMARY OF THE INVENTION
[0009] An aspect of the present invention is to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below.
[0010] Accordingly, in one aspect of the present invention relates to a Multi-Channel Multi-Octave Front End Receiver (100), the receiver comprising: at least one Radio Frequency module (RFM) (103) having at least two RF channels, each channel having two RF input ports, wherein one input (11) port of each channel is configured to receive RF signals in plurality of bands from an antenna and other input (12) port of each channel is configured to receive Built-in Test (BIT) signals to enable testing and perform diagnostics of the RF module, at least one power distribution, control and auto-detection module (PDCAM) (102) configured to provide required voltages and controls to the receiver and configured to detect the presence of RF signals based on a threshold value, wherein the PDCAM (102) module comprises a logarithmic detector for each sub-high frequency band which detects the incoming RF signals and at least one Local Oscillator module (LOM) (101) configured to generate fixed frequencies in plurality of bands for down-conversion of the received signals from the antenna.
[0011] Other aspects, advantages, and salient features of the invention will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses exemplary embodiments of the invention.
BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS
[0012] The detailed description is described with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the drawings to reference like features and modules.
[0013] Figure 1 shows a stack up diagram of Multi-channel Multi-octave Front End Receiver with integrated fast switching local oscillator and auto-detector according to an exemplary implementation of the present disclosure/ invention.
[0014] Figure 2 shows a Radio Frequency Module (RFM) of the receiver according to an exemplary implementation of the present disclosure/invention.
[0015] Figure 3 shows an RFM - first stage of ultra-wide band signal processing path for channel 1 according to an exemplary implementation of the present disclosure/invention.
[0016] Figure 4 shows an RFM - sub-frequency band processing path according to an exemplary implementation of the present disclosure/invention.
[0017] Figure 5 shows an RFM - down conversion path for high sub-frequency band according to an exemplary implementation of the present disclosure/invention.
[0018] Figure 6 shows an RFM - output stage for all the processed paths according to an exemplary implementation of the present disclosure/invention.
[0019] Figure 7 shows LOM - clock and reference signal generation section according to an exemplary implementation of the present disclosure/invention.
[0020] Figure 8 shows LOM – LO signal generation section according to an exemplary implementation of the present disclosure/invention.
[0021] Figure 9 shows LOM – LO signal selection and distribution section according to an exemplary implementation of the present disclosure/invention.
[0022] Figure 10 shows PDCAM - auto-detection section according to an exemplary implementation of the present disclosure/invention.
[0023] Figure 11 shows LOM to RFM wideband vertical microwave co-axial transition according to an exemplary implementation of the present disclosure/invention.
[0024] It should be appreciated by those skilled in the art that any block diagrams herein represent conceptual views of illustrative methods embodying the principles of the present disclosure. Similarly, it will be appreciated that any flow charts, flow diagrams, and the like represent various processes which may be substantially represented in computer readable medium and so executed by a computer or processor, whether or not such computer or processor is explicitly shown.
DETAILED DESCRIPTION OF THE INVENTION
[0025] The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of exemplary embodiments of the invention as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the embodiments described herein can be made without departing from the scope and spirit of the invention. In addition, descriptions of well-known functions and constructions are omitted for clarity and conciseness.
[0026] The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the invention. Accordingly, it should be apparent to those skilled in the art that the following description of exemplary embodiments of the present invention are provided for illustration purpose only and not for the purpose of limiting the invention as defined by the appended claims and their equivalents.
[0027] It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
[0028] By the term “substantially” it is meant that the recited characteristic, parameter, or value need not be achieved exactly, but that deviations or variations, including for example, tolerances, measurement error, measurement accuracy limitations and other factors known to those of skill in the art, may occur in amounts that do not preclude the effect the characteristic was intended to provide.
[0029] Figures discussed below, and the various embodiments used to describe the principles of the present disclosure in this patent document are by way of illustration only and should not be construed in any way that would limit the scope of the disclosure. Those skilled in the art will understand that the principles of the present disclosure may be implemented in any suitably arranged communications system. The terms used to describe various embodiments are exemplary. It should be understood that these are provided to merely aid the understanding of the description, and that their use and definitions in no way limit the scope of the invention. Terms first, second, and the like are used to differentiate between objects having the same terminology and are in no way intended to represent a chronological order, unless where explicitly stated otherwise. A set is defined as a non-empty set including at least one element.
[0030] In the following description, for purpose of explanation, specific details are set forth in order to provide an understanding of the present disclosure. It will be apparent, however, to one skilled in the art that the present disclosure may be practiced without these details. One skilled in the art will recognize that embodiments of the present disclosure, some of which are described below, may be incorporated into a number of systems.
[0031] However, the systems and methods are not limited to the specific embodiments described herein. Further, structures and devices shown in the figures are illustrative of exemplary embodiments of the presently disclosure and are meant to avoid obscuring of the presently disclosure.
[0032] It should be noted that the description merely illustrates the principles of the present invention. It will thus be appreciated that those skilled in the art will be able to devise various arrangements that, although not explicitly described herein, embody the principles of the present invention. Furthermore, all examples recited herein are principally intended expressly to be only for explanatory purposes to help the reader in understanding the principles of the invention and the concepts contributed by the inventor to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Moreover, all statements herein reciting principles, aspects, and embodiments of the invention, as well as specific examples thereof, are intended to encompass equivalents thereof.
[0033] The various embodiments of the present invention describe about a Multi-Channel Multi-Octave Front End Receiver (MCMOFER), with ultra-wideband (> 4 octaves) capability, ranging from L-band to Ku-band with a wide instantaneous signal processing bandwidth. The MCMOFER has very high-speed switching Local Oscillator (LO) and has the capability to auto-detect the incoming Radar frequency band. The MCMOFER finds its application in Target detect and identify Receivers.
[0034] The wide instantaneous signal processing bandwidth, along with high speed switching LO and the auto detection capability of MCMOFER enhances the speed of detection of the radar frequency band, making MCMOFER an ideal front end receiver for Target detect and identify System (TDIS).
[0035] The Multi-Channel Multi-Octave Front End Receiver (MCMOFER) is preceded by the antenna of the Target detect and identify System (TDIS). The multiplexer separates the incoming ultra-wideband RF signal into sub-frequency bands. The auto-detector detects the incoming signal band and accordingly the local oscillator is switched to the frequency required for down-conversion. The received signal is then converted to a low frequency signal for further digital processing and identification of the radar.
[0036] The Multi-Channel Multi-Octave Front End Receiver (MCMOFER) (100) comprises of three sub modules: Radio Frequency (RF) module, Power Distribution, Control and Auto-detection module and Local Oscillator (LO) module. The RF module does the front-end analog RF signal processing. The Power Distribution, Control and Auto-detection module supplies the required voltages and controls and also encompasses the auto-detection process steps. The fast switching Local oscillator (LO) module generates fixed frequencies in K-band, Ku-band and X-band for down conversion of the received signal.
[0037] In one embodiment, the present invention provides a Multi-channel Multi-octave Front End Receiver with integrated fast switching Local oscillator and Auto-detector comprises of:
i. Radio Frequency module (RFM) for processing ultra-wideband (> 4 octaves) frequency signals, ranging from L band to Ku band and down converts to L-band to C-band, by maintaining spurious and harmonics below sensitivity level.
ii. RFM has a high instantaneous signal processing bandwidth and wide dynamic range.
iii. RFM has the capability to limit the level of high power signal from antenna port to prevent damage of other circuitry.
iv. RFM has port for system level debugging having high isolation with respect to the port connected to Antenna.
v. Ultra-wideband signals are separated into sub-high frequency bands with high isolation among them for further processing in RFM.
vi. Sub-high frequency bands of RFM has very low noise figure and moderate gain.
vii. Local oscillator module (LOM) is fast switching and generates K-band, Ku-band and X-band frequencies and compactly integrated in the receiver.
viii. Integrated Power Distribution, Control and Auto-detection module (PDCAM) to increase the speed of threat detection.

[0038] In one embodiment, the RFM limits the level of high power signal from antenna port by using an ultra-wideband limiter switch having a very high isolation between the ports which supports in removing the interference of unwanted incoming signal from the adjacent ports. Further, one of the ports is used for Built-in test (BIT), which helps in self-test and performing diagnostics.
[0039] In one embodiment, the RFM receives the wideband signals (L to Ku Band) and separates into five sub-high frequency band signals using a multiplexer, providing high isolation among these signals. Further the sub-high frequency band signals are connected to RF switches, which provide high isolation and prevents interference between the sub-high frequency band signals.
[0040] In one embodiment, the RFM has independent Low Noise Amplifiers (LNA) in each sub-high frequency bands, which aids in achieving low noise figure and moderate gain.
[0041] In one embodiment, the RFM comprises of: Three port, wide-band RF mixer with one port configured to receive a local oscillator signal and a second input configured to receive a sub-high frequency band signal. Output of the mixer is a down converted signal from L-band to C-band. The signal is filtered using RF filter for limiting the level of unintended frequency components, resulting in a down converted low frequency signal with low spurious and harmonics.
[0042] In one embodiment, the LOM is fast switching, designed using Phase Locked Loop (PLL) ICs (Integrated Circuits), which generates K-band, Ku-band and X-band frequencies. The output of PLL ICs are connected to wideband RF switches with very high isolation. Depending on the Auto detection, the programming device controls the RF switches to switch to the required LO frequency. The very high switching speed of LOM aids in fast threat detection.
[0043] In one embodiment, the Power Distribution, Control and Auto-detection module (PDCAM) comprises of: wideband logarithmic detector for each sub-high frequency band, which detects the incoming RF signal and the auto-detection process steps incorporated in the programming device detects the presence of RF signal based on a threshold value. This process highly enhances the speed of threat detection in Target detect and identify System (TDIS).
[0044] In one embodiment, the Multi-Channel Multi-Octave Front End Receiver (MCMOFER) architecture comprises of: compact integration of the LOM with RFM, achieved using wideband vertical microwave co-axial transition. The PDCAM is sandwiched in between LOM and RFM to ease the power distribution for LOM and RFM.
[0045] In one embodiment, the Multi-Channel Multi-Octave Front End Receiver (MCMOFER) is capable of spanning over broad frequency signal spectrum from L-band to Ku-band.
[0046] In one embodiment, the MCMOFER has capability to receive input power over wide dynamic range.
[0047] In one embodiment, the Multi-Channel Multi-Octave Front End Receiver (MCMOFER) has capability to convert ultra-wide band signals (L-band to Ku-band) to low frequency band (L-band to C-band), by maintaining spurious and harmonics below sensitivity level.
[0048] In one embodiment, the MCMOFER has Port for system level debugging with high isolation with respect to the port connected to Antenna of TDIS.
[0049] In one embodiment, the MCMOFER has capability to limit the level of high power signal from antenna port to prevent damage of other circuitry.
[0050] In one embodiment, the MCMOFER has integrated fast switching Local Oscillator, which generates fixed frequencies in K-band, Ku-band and X-band for down-conversion of the received signals.
[0051] In one embodiment, the MCMOFER has auto-detection capability to detect the band in which the signal is received for further digital processing and identification of the radar. This capability increases the speed of threat detection.
[0052] Figure 1 shows a stack up diagram of Multi-channel Multi-octave Front End Receiver with integrated fast switching local oscillator and auto-detector according to an exemplary implementation of the present disclosure/ invention.
[0053] The figure shows a stack up diagram of Multi-Channel Multi-Octave Front End Receiver (MCMOFER). The MCMOFER (100) comprises of three sub modules: (101) Local Oscillator (LO) Module, (102) Power Distribution, Control and Auto-detection Module and (103) Radio Frequency (RF) module.
[0054] In one embodiment, the Multi-Channel Multi-Octave Front End Receiver (100), the receiver comprising: at least one Radio Frequency module (RFM) (103) having at least two RF channels, each channel having two RF input ports, wherein one input (11) port of each channel is configured to receive RF signals in plurality of bands from an antenna and other input (12) port of each channel is configured to receive Built-in Test (BIT) signals to enable testing and perform diagnostics of the RF module, at least one power distribution, control and auto-detection module (PDCAM) (102) configured to provide required voltages and controls to the receiver and configured to detect the presence of RF signals based on a threshold value, wherein the PDCAM (102) module comprises a logarithmic detector for each sub-high frequency band which detects the incoming RF signals and at least one Local Oscillator module (LOM) (101) configured to generate fixed frequencies in plurality of bands for down-conversion of the received signals from the antenna.
[0055] Further, each channel of the Radio Frequency module (RFM) (103) includes at least one output port which delivers the required down converted signals lying in the L and C frequency bands.
[0056] The Radio Frequency module (RFM) (103) is further configured to receive ultra-wideband frequency signals and separate the received signals into sub-high frequency bands with high isolation, wherein the Radio Frequency module (RFM) comprises: at least one high-power limiter (301) configured to receive RF signals in plurality of bands from the antenna to prevent damage of successive circuits of the receiver in case of plurality of high-power input signals (11) received, at least one wide band single pole three way switching device (302) configured to receive the RF signals (11) from the limiter and configured to receive Built-in Test (BIT) signals (12), and switch between the Inputs signals (11) and (12) based on high isolation provided in the wide band single pole three way switching device (302) and at least one multi-octave wide band multiplexer (303) configured to receive the RF signals from the wide band single pole three way switching device (302) and separate the received RF signals into plurality of sub-high frequency bands signals (figure 3).
[0057] The Radio Frequency module (RFM) is further configured to receive the sub-high frequency bands signals with high isolation for further processing, wherein the Radio Frequency module (RFM) further comprises: at least one low noise amplifier (401) configured to receive the sub-high frequency bands signals and amplify the received signals, at least one two-way power divider (402) configured to receive the amplified signals and divide the amplified signals, where one of the divided signal is indicated as amplified output A1, A2… A5 (An) and the other divided signal is again amplified using at least one low noise gain block (403), at least one wideband frequency detector (404) configured to receive the amplified signals D1, D2… D5 (Dn) from the low noise gain block (403) and detect the amplified output and provides the amplified output to the PDCAM (102) module (figure 4).
[0058] The Radio Frequency module (RFM) further comprises: a plurality of low pass filters (501) configured to receive the amplified output (A3, A4, A5) from the two-way power divider (402) and filter the amplified output, wherein the amplified output includes high frequency band signals (C, X and Ku), at least one C to Ku band single pole three way switching device (502) configured to receive the filtered high frequency band signals (C, X and Ku) and switch between different high frequency band signals, at least one wide band C to Ku band mixer (503) configured to receive and down convert C to Ku band signals to S-C band signals, wherein the wide band C to Ku band mixer (503) is configured to receive filtered LO signals from the local oscillator (102), wherein the lo signal is at least one fixed frequency signal,a low pass filter (504) configured to receive the down converted signals, filter unwanted frequency in the received signals, an amplifier (505) configured to receive the filtered signal from the low pass filter (504) and amplify the received signal using gain block (505), a low pass filter (506) configured to receive the amplified signal from the amplifier (505) and reduce the signal strength of unwanted signals present in frequency ranges other than S and C frequency bands and at least one equalizer (507) configured to receive the signal from the low pass filter (506) and maintain constant gain over the down converted frequency range in S and C band and obtain an intermediate frequency (IF) signal (figure 5).
[0059] The Radio Frequency module (RFM) is further configured to receive lower sub-frequency processed signals (A1 and A2) in S and C band and process the lower sub-frequency processed signals directly to the output stage, wherein the Radio Frequency module (RFM) further comprises: at least one S and C band single pole three way switching device (601) configured to receive the lower sub-frequency processed signals (A1, A2) and the intermediate frequency (IF) signal, and switch between lower sub-frequency processed signals (A1, A2) and IF signal, at least one attenuator (602) and at least one gain block (603) configured to maintain signal strength for maintaining the sensitivity of the MCMOFER (100) and at least one low pass filter (604) configured to receive and reduce the unwanted frequency signals other than S and C band and obtain down converted low frequency signal (figure 6).
[0060] The Local Oscillator module (LOM) is configured with fast switching technique and is constructed using Phase Locked Loop (PLL) IC which generates different frequency bands and further an output of Local Oscillator module (LOM) is amplified, filtered and connected to RFM switches with very high isolation. The RF Module switches quickly to required LO frequency signals from different frequency bands based on auto detection by the auto-detection module (PDCAM), wherein high switching speed of LOM aids in fast threat detection.
[0061] Figure 2 shows a Radio Frequency Module (RFM) of the receiver according to an exemplary implementation of the present disclosure/invention.
[0062] The figure shows a Radio Frequency Module (RFM) of the receiver consisting of dual RF channels. As shown in Fig.2, (201) is channel 1 and (202) is channel 2. Each channel has two input ports and one output port. One of the input ports receives signals in L to Ku band from antenna of the TDIS. The other port is used as a Built-in Test (BIT) port provided as part of the module to enable testing and perform diagnostics. The output port delivers the down converted intermediate signal in the frequency band spanning from L to C band.
[0063] Figure 3 shows an RFM -first stage of ultra-wide band signal processing path for channel 1 according to an exemplary implementation of the present disclosure/invention.
[0064] The figure shows First stage of ultra-wide band signal processing path for channel 1. The input (11) is the received signals from the antenna and input (12) is BIT port signals. (301) is a high power limiter used to prevent damage of the successive circuit in case of high power received input (11). (302) is a wide band single pole three way switching device used to switch between Input (11), Input (12) and termination that is controlled by the programming device (1010) in (102). The signals of Input (11) are not present at the output when the control is given for Input (12), due to high isolation provided in (302). (303) is a multi-octave ultra-wide band multiplexer, which separates the L to Ku Bands into five sub-band high frequency signal paths: Path 1, 2…5 for further processing.
[0065] Figure 4 shows an RFM – sub-frequency band processing path according to an exemplary implementation of the present disclosure/invention.
[0066] The figure shows the sub- frequency band processing paths. Each Path 1, 2…5 indicated as Path n is amplified using a low noise amplifier (401). (402) is a two-way power divider used to split the amplified output. One of the power-divided output is indicated as amplified output A1, A2… A5 (An). The other power-divided path is again amplified using (403) low noise gain block. (404) is a wideband logarithmic detector, which detects the amplified output and gives respective voltages for the signal strength. The detected output in each path is D1, D2… D5 indicated as Dn. The Dn is further processed for auto-detection in (102).
[0067] Figure 5 shows an RFM - down conversion path for high sub-frequency band according to an exemplary implementation of the present disclosure/invention.
[0068] The figure shows the down conversion path for higher sub-frequency band. A3, A4 and A5, which spans from C to Ku band are filtered using low pass filters (501). (502) is a C to Ku band single pole three way switching device used to switch between filtered inputs A3, A4 and A5, which is controlled by the programming Device (1010) in (102) based on the auto-detection paths D1, D2… D5. The signals A3 are not present at the output when the control is provided for Input A4 or A5, due to high isolation provided in (502). Similarly signals A4 are not present at the output when the control is provided for Input A3 or A5. (503) is a wide band C to Ku band mixer which down converts C to Ku band signals of A3, A4 and A5 to S-C band signals. The LO signal (907) for channel 1 is amplified using (509) and processed through low pass filter (508). This filtered output is used as LO input for (503). The down converter signals are processed using low pass filters (504) and (506) and amplified using gain block (505). (504) and (506) helps in reducing the signal strength of unwanted signals present in frequency ranges other than the frequency bands of S and C. (507) is an equalizer, which is used to maintain flat gain response over the down converter frequency range in S and C band. The IF signal is the down converted signal of high sub-frequency band.
[0069] Figure 6 shows an RFM - output stage for all the processed paths according to an exemplary implementation of the present disclosure/invention.
[0070] The figure shows the output stage for all the processed paths. The lower sub-frequency processed signals A1, A2 that are in L to C band are processed directly to the Output stage. (601) is an L to C band single pole three way switching device used to switch between A1, A2 and IF signal, which is controlled by the programming device (1010) in (102). The signals A1 are not present at the output when the control is provided for Input A2 or for IF signals, due to high isolation provided in (601). Similarly signals IF are not present at the output when the control is given for is provided for Input A1 or A2. (602) is an attenuator and (603) is a gain block, which are used to maintain signal strength for maintaining the sensitivity of the MCMOFER. (604) is a low pass filter used at the final output stage for reducing the unwanted frequency signals other than L to C band.
[0071] Figure 7 shows LOM – clock and reference signal generation section according to an exemplary implementation of the present disclosure/invention.
[0072] The figure shows the clock and reference signal generation section of Local Oscillator module (101). (701) is a reference oscillator. (702) is a low pass filter which is connected to the output of the reference oscillator. (703) is an amplifier to amplify the filtered output. (704) is a two way power divider. (705) is a two way power divider with (706) as one output and (707) as the other output. (711) is a two way power divider with (708) as one output and the other output is connected to (710), which is sine to square converter circuit, the output of which is (709) which is used as clock signal for the programming device (1010) used in the system.
[0073] Figure 8 shows LOM – signal generation section according to an exemplary implementation of the present disclosure/invention.
[0074] The figure shows the signal generation section of the LO module (101). (801) is a Phase Locked Loop (PLL) chip, which generates K-band signal by using a reference signal (706). The K-band signal is then filtered using (804), which is a band pass filter. The output of (804) is then connected to (807), which is an RF switch for isolation. The output of (807) is then amplified using (810), which is an amplifier and filtered using (813), which is a band pass filter. (802) is a Phase Locked Loop (PLL) chip, which generates Ku-band signal by using a reference signal (707). The Ku-band signal is then filtered using (805), which is a band pass filter. The output of (805) is then connected to (808), which is an RF switch for isolation. The output of (808) is then amplified using (811), which is an amplifier and filtered using (814), which is a band pass filter. (803) is a Phase Locked Loop (PLL) chip, which generates X-band signal by using a reference signal (708). The X-band signal is then filtered using (806), which is a band pass filter. The output of (806) is then connected to (809), which is an RF switch for isolation. The output of (809) is then amplified using (812), which is an amplifier and filtered using (815), which is a band pass filter.
[0075] Figure 9 shows LOM – signal selection section according to an exemplary implementation of the present disclosure/invention.
[0076] The figure shows the signal selection section of the LO module (101). (901) is a switch with three inputs and one output. The first input is connected to (816), which is the K-band signal. The second input is connected to (817), which is the Ku-band signal and third input is connected to (818), which is the X-band signal. The output of the switch (901) is connected to (902), which is a two way power divider with two output ports. The first output port is connected to (903), which is an amplifier. The output of the amplifier is then connected to (905), which is a low pass filter. (907) is the final LO output for channel 1 which is fed to the RF module (103) using the feed-through (1101). The second output port is connected to (904), which is an amplifier. The output of the amplifier is then connected to (906), which is a low pass filter. (908) is the final LO output for channel 2 which is fed to the RF module (103) using the feed-through (1102).
[0077] Figure 10 shows PDCAM - auto-detection section according to an exemplary implementation of the present disclosure/invention.
[0078] The figure shows the auto-detection section of the Power Distribution, Control and Auto-detection module. (1001) is the wideband logarithmic detector of sub-band frequency channel 1. The output of the detector is connected to (1004), which is an operational amplifier. The output of operational amplifier is connected to (1007), which is an Analog to Digital Converter (ADC). (1002) is the wideband logarithmic detector of sub-band frequency channel 2. The output of the detector is connected to (1005), which is an operational amplifier. The output of operational amplifier is connected to (1008), which is an Analog to Digital Converter (ADC). (1003) is the wideband logarithmic detector of sub-band frequency channel ‘n’. The output of the detector is connected to (1006), which is an operational amplifier. The output of operational amplifier is connected to (1009), which is an Analog to Digital Converter (ADC). The output of the ‘n’ (n depends on the number of sub-band frequency channel) ADCs (1007, 1008, 1009) are connected to (1010), which a programming device encompassing the auto-detection process steps.
[0079] Figure 11 shows LOM to RFM wideband vertical microwave co-axial transition according to an exemplary implementation of the present disclosure/invention.
[0080] The figure shows the RF feed-through architecture used to feed the LO signal to the RF module. (1101) is the RF feed-through for channel 1 and (1102) is the RF feed-through for channel 2. (1101) and (1102) are low profile high frequency spring loaded RF bullets connected to low profile high frequency panel mount connectors.
[0081] Figures are merely representational and are not drawn to scale. Certain portions thereof may be exaggerated, while others may be minimized. Figures illustrate various embodiments of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
[0082] In the foregoing detailed description of embodiments of the invention, various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments of the invention require more features than are expressly recited in each claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Thus, the following claims are hereby incorporated into the detailed description of embodiments of the invention, with each claim standing on its own as a separate embodiment.
[0083] It is understood that the above description is intended to be illustrative, and not restrictive. It is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined in the appended claims. Many other embodiments will be apparent to those of skill in the art upon reviewing the above description. The scope of the invention should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled. In the appended claims, the terms “including” and “in which” are used as the plain-English equivalents of the respective terms “comprising” and “wherein,” respectively.
,CLAIMS:

1. A Multi-Channel Multi-Octave Front End Receiver (100), the receiver comprising:
at least one Radio Frequency module (RFM) (103) having at least two RF channels, each channel having two RF input ports, wherein one input (11) port of each channel is configured to receive RF signals in plurality of bands from an antenna and other input (12) port of each channel is configured to receive Built-in Test (BIT) signals to enable testing and perform diagnostics of the RF module;
at least one power distribution, control and auto-detection module (PDCAM) (102) configured to provide required voltages and controls to the receiver and configured to detect the presence of RF signals based on a threshold value, wherein the PDCAM (102) module comprises a logarithmic detector for each sub-high frequency band which detects the incoming RF signals; and
at least one Local Oscillator module (LOM) (101) configured to generate fixed frequencies in plurality of bands for down-conversion of the received signals from the antenna.

2. The receiver as claimed in claim 1, wherein each channel of the Radio Frequency module (RFM) (103) includes at least one output port which delivers the required down converted signals lying in the L and C frequency bands.

3. The receiver as claimed in claim 1, wherein the Radio Frequency module (RFM) (103) is further configured to receive ultra-wideband frequency signals and separate the received signals into sub-high frequency bands with high isolation, wherein the Radio Frequency module (RFM) comprises:
at least one high-power limiter (301) configured to receive RF signals in plurality of bands from the antenna to prevent damage of successive circuits of the receiver in case of plurality of high-power input signals (11) received;
at least one wide band single pole three way switching device (302) configured to receive the RF signals (11) from the limiter and configured to receive Built-in Test (BIT) signals (12), and switch between the Inputs signals (11) and (12) based on high isolation provided in the wide band single pole three way switching device (302); and
at least one multi-octave wide band multiplexer (303) configured to receive the RF signals from the wide band single pole three way switching device (302) and separate the received RF signals into plurality of sub-high frequency bands signals.

4. The receiver as claimed in claims 1 and 3, wherein the Radio Frequency module (RFM) is further configured to receive the sub-high frequency bands signals with high isolation for further processing, wherein the Radio Frequency module (RFM) further comprises:
at least one low noise amplifier (401) configured to receive the sub-high frequency bands signals and amplify the received signals;
at least one two-way power divider (402) configured to receive the amplified signals and divide the amplified signals, where one of the divided signal is indicated as amplified output A1, A2… A5 (An) and the other divided signal is again amplified using at least one low noise gain block (403);
at least one wideband frequency detector (404) configured to receive the amplified signals D1, D2… D5 (Dn) from the low noise gain block (403) and detect the amplified output and provides the amplified output to the PDCAM (102) module.

5. The receiver as claimed in any one of the claims 1 to 4, wherein the Radio Frequency module (RFM) further comprises:
a plurality of low pass filters (501) configured to receive the amplified output (A3, A4, A5) from the two-way power divider (402) and filter the amplified output, wherein the amplified output includes high frequency band signals (C, X and Ku);
at least one C to Ku band single pole three way switching device (502) configured to receive the filtered high frequency band signals (C, X and Ku) and switch between different high frequency band signals;
at least one wide band C to Ku band mixer (503) configured to receive and down convert C to Ku band signals to S-C band signals, wherein the wide band C to Ku band mixer (503) is configured to receive filtered LO signals from the local oscillator (102), wherein the lo signal is at least one fixed frequency signal;
a low pass filter (504) configured to receive the down converted signals, filter unwanted frequency in the received signals;
an amplifier (505) configured to receive the filtered signal from the low pass filter (504) and amplify the received signal using gain block (505),
a low pass filter (506) configured to receive the amplified signal from the amplifier (505) and reduce the signal strength of unwanted signals present in frequency ranges other than S and C frequency bands; and
at least one equalizer (507) configured to receive the signal from the low pass filter (506) and maintain constant gain over the down converted frequency range in S and C band and obtain an intermediate frequency (IF) signal.

6. The receiver as claimed in any one of the claims 1 to 5, wherein the Radio Frequency module (RFM) is further configured to receive lower sub-frequency processed signals (A1 and A2) in S and C band and process the lower sub-frequency processed signals directly to the output stage, wherein the Radio Frequency module (RFM) further comprises:
at least one S and C band single pole three way switching device (601) configured to receive the lower sub-frequency processed signals (A1, A2) and the intermediate frequency (IF) signal, and switch between lower sub-frequency processed signals (A1, A2) and IF signal;
at least one attenuator (602) and at least one gain block (603) configured to maintain signal strength for maintaining the sensitivity of the MCMOFER (100); and
at least one low pass filter (604) configured to receive and reduce the unwanted frequency signals other than S and C band and obtain down converted low frequency signal.

7. The receiver as claimed in claim 1, wherein the Radio Frequency module (RFM) is configured to process ultra-wideband (> 4 octaves) frequency signals, ranging from L band to Ku band and down convert to L-band to C-band, by maintaining spurious and harmonics below sensitivity level.

8. The receiver as claimed in claim 1, wherein the Local oscillator module (LOM) is a fast-switching circuit and generates K-band, Ku-band and X-band frequencies and is compactly integrated in the receiver.

9. The receiver as claimed in claim 3, further comprises an ultra-wideband limiter switch configured to limit a level of high-power signal from antenna port and further the ultra-wideband limiter switch having a very high isolation between the ports which supports in removing the interference of unwanted incoming signal from the adjacent ports.

10. The receiver as claimed in claim 1, wherein the Local Oscillator module (LOM) is configured with fast switching technique and is constructed using Phase Locked Loop (PLL) IC which generates different frequency bands and further an output of Local Oscillator module (LOM) is amplified, filtered and connected to RFM switches with very high isolation.

12. The receiver as claimed in claim 1, wherein the RF Module switches quickly to required LO frequency signals from different frequency bands based on auto detection by the auto-detection module (PDCAM), wherein high switching speed of LOM aids in fast threat detection.

13. The receiver as claimed in claim 1, wherein an integration of the LOM with RFM is achieved using vertical microwave co-axial transition and the PDCAM is sandwiched in between LOM and RFM to ease the power distribution for LOM and RFM.