Claims:1. An apparatus (100) with integrated control, the apparatus comprising:
a housing (202) with a narrow contact edge, one or more power amplifiers (114-1, 114-2) are optimally placed closer to the narrow contact edge of the housing, wherein low RF input is received from an exciter unit and provide sufficient gain in different stages to generate high RF output power over an operational frequency band; and
a high voltage medium current regulatory circuit (124) configured in the apparatus, said high voltage medium current regulatory circuit (124) adapted to adjust the regulated output voltage and implemented to adjust the final output power for said one or more power amplifiers (114-1, 114-2), wherein heat generated from the one or more power amplifiers (114-1, 114-2) is transferred to a liquid cooled system through the narrow contact edge.

2. The apparatus as claimed in claim 1, wherein said one or more power amplifiers (114-1, 114-2) are optimally placed closer to the narrow contact edge of 35mm of the housing (202), which is in direct contact to a cold plate such that the heat around 200W is transferred from the junction of the one or more power amplifiers to the liquid cooling system external to the apparatus.

3. The apparatus as claimed in claim 1, wherein the high voltage medium current regulatory circuit (124) comprise a shunt regulator (126-1), a standard low voltage series regulator (126-2) and a power negative-positive-negative (NPN) Darlington transistor (126-3) wherein a combination of the standard low voltage series regulator (126-2) and the shunt regulator (126-1) are used with adjustable feature for better ripple reduction and to provide regulated direct current (DC) voltage output for the one or more power amplifiers to adjust the final output power for said one or more power amplifiers (114-1, 114-2) .

4. The apparatus as claimed in claim 1, wherein the apparatus (100) comprises a drain pulsing circuit (128) adapted to generate pulsed voltage, the drain pulsing circuit comprises high-speed P-channel metal–oxide–semiconductor field-effect transistor (MOSFETs) having low internal input resistance, output resistance and capacitance to ensure a fast rise and fall time of less than 50ns for the pulsed final output power.

5. The apparatus as claimed in claim 1, where the apparatus (100) comprises a monitor and control card (106) that comprises a FPGA that monitors the health of the apparatus and reports the status through a monitoring and control interface using low voltage differential signaling (LVDS) lines and to cut-off the drain voltages of the one or more power amplifiers (114-1, 114-2) from entering in longer pulse width and high duty operations, thereby increasing the reliability of the one or more power amplifiers.

6. The apparatus as claimed in claim 1, wherein the apparatus comprises a temperature-sensing circuitry (130) that monitors the temperature to generate alarms and trips off the one or more power amplifiers (114-1, 114-2) in case of extreme over-heating, wherein the temperature-sensing circuitry enables the one or more power amplifiers to operate in high temperature emergency with settable threshold temperature.

7. A method (500) of operating an apparatus, the method comprising:
placing (502) one or more power amplifiers optimally closer to a narrow contact edge of a housing, low RF input is received from an exciter unit and provide sufficient gain in different stages to generate high RF output power over an operational frequency band, the one or more power amplifiers configured in the apparatus; and
adjusting (504), by a high voltage medium current regulatory circuit configured in the apparatus, regulated output voltage and implemented to adjust the final output power for the one or more power amplifiers, wherein heat generated from the one or more power amplifiers is transferred to a liquid cooled system through the narrow contact edge.
, Description:TECHNICAL FIELD
[0001] The present disclosure relates, in general, to pulsed Radar systems, and more specifically, relates to a liquid cooled solid-state pulsed power amplifier with an integrated control system.

BACKGROUND
[0002] In pulsed RADAR systems, a power amplifier (PA) is a key component, which provides high power during transmission to cater for the Radar range requirements. The PA designs are usually tube-based or solid state-based. Tube-based amplifiers need a high voltage power supply in order of kilovolt to operate whereas solid state-based amplifier needs low DC voltage i.e., a few tens of Volt for its operation. Also, the tube-based amplifiers can generate power of the order of kilowatts only for a small duty cycle, however, by using the advanced techniques in pulse compressions these tubes-based amplifiers are being replaced by solid-state RF power amplifier (SSPA), which can generate power of few 100s of watts and can operate at duty cycles, which are close to 25%.
[0003] The power of 100s of watts in solid-state PPAs can be generated by combining multiple RF devices. The main advantage of combining multiple devices is during the failure of even one device the PPA continues to deliver a lower o/p power, hence the concept of graceful degradation is incorporated but for the tube-based amplifier, the tube is a single point of failure hence solid state-based amplifier gives a better value of mean time between failure (MTBF) as compared to the tube-based amplifier. However, there is a limitation in combining the number of RF devices as beyond a certain number combining the RF devices is no longer efficient and cooling the parallel devices becomes challenging. Hence it is always beneficial to combine the power from devices, which generate high power.
[0004] One of the challenging tasks in designing a solid-state amplifier, which uses high power PA devices is to quickly transfer the concentrated heat from these small profile device junctions to metal chassis and then to the external environment, wherein the available cooling systems may take away the heat generated. Generally, the convection cooled amplifiers use either forced air cooling or liquid cooling systems.
[0005] An example of such a power amplifier is recited in a patent US5793253, entitled “high-power solid-state microwave transmitter”. The patent describes the generation of high power by splitting a pre-amplified signal into a plurality of signals, amplifying the lower-level signals so obtained, and then recombining the amplified signals. Fail-soft operation is established by providing switching redundant amplifiers. Another example of the power amplifier is recited in a patent US8004364B2, entitled “high power RF solid-state power amplifier system”. The patent describes the generation of high power by dividing the combining stages into four pallets and then combines these pallets to achieve high power. Automatic level control protection circuitry based on PIN diode protects the amplifier & maintain a substantial amplifier power output.
[0006] United States Patent US4727337 titled “protection circuit for power amplifier, describes the design of an improved power controller and protection circuit to regulate the RF output power of a radio transmitter and to protect its RF amplifier from overload damage. Protection circuitry is implemented by cutting off the DC supply of the driver stage amplifier based on power status detected and other status. United States Patent US 5111084 titled “Low loss Drain Pulse Circuit for Solid-state Microwave Power Amplifier” describes the design of a drain pulsing circuit for intermittently applying electric power to the drain of a solid stare amplifier. The capacitor stores here the charge during an off cycle and provide the high current when control pulse is generated. The pulsing circuit is realized using n-channel MOSFET for the GaAs based amplifier where the required voltage is 10V typical.
[0007] Yet another example of the power amplifier is recited in a patent US8346189B2 titled “power amplifier architecture” describes the implementations and examples of power amplifier devices, systems and techniques for amplifying RF signals, including power amplifier system based on Composite Right and Left-Handed (CRLH) metamaterial (MTM) structures.
[0008] Although multiple power amplifiers exist today, these power amplifiers suffer from significant drawbacks. Therefore, it is desired to develop a simple, efficient and cost-effective means that combines power from high power-based amplifiers to generate the output power and to transfer the heat generated from high power-based amplifiers to the liquid-cooled system.

OBJECTS OF THE PRESENT DISCLOSURE
[0009] An object of the present disclosure relates, in general, to pulsed Radar systems, and more specifically, relates to a liquid cooled solid-state pulsed power amplifier with an integrated control system.
[0010] Another object of the present disclosure is to provide an apparatus that combines power from high power amplifiers to generate the output power effectively.
[0011] Another object of the present disclosure is to provide an apparatus that transfers heat generated from the power amplifiers to a liquid-cooled system.
[0012] Another object of the present disclosure is to provide an apparatus that enables to adjust the drain voltages of the power amplifiers which in turn may enable to adjust the output power generated from these power amplifiers.
[0013] Another object of the present disclosure is to provide an apparatus that ensures fast rise and fall time to enable the amplifier to generate a very low pulse width.
[0014] Another object of the present disclosure prevents the pulsed power amplifier from entering in longer pulse width and high duty operations and hence increasing the reliability of the power amplifiers
[0015] Another object of the present disclosure is to provide an apparatus that provides a uniform thermal gradient.
[0016] Yet another object of the present disclosure is to provide an apparatus with temperature shut down override facility which enables the apparatus to operate during an emergency for a short duration.

SUMMARY
[0017] The present disclosure relates, in general, to pulsed Radar systems, and more specifically, relates to a liquid cooled solid-state pulsed power amplifier with an integrated control system. Existing apparatus typically combine the number of RF devices, where beyond a certain number combining the RF devices is no longer efficient and cooling the parallel devices becomes challenging. The main objective of the present disclosure is to solve the technical problem as recited above by combining power from high power Gallium Nitride (GaN) based amplifiers to generate the output power and transferring the heat generated from the high-power Gallium Nitride (GaN) based amplifiers to the liquid-cooled system through a thin narrow edge contact of the power amplifier. The proposed liquid-cooled solid-state pulsed power amplifier comprises a drain pulsing circuit for GaN device that uses p-channel metal–oxide–semiconductor field-effect transistor (MOSFET) instead of n-channel to achieve narrow pulse width application. The drain voltage cut-off of the power amplifier devices performed during protection circuitry implementation as against using Positive-Intrinsic–Negative (PIN) diodes with feedback.
[0018] The present disclosure aims at combining power from high power gallium nitride (GaN) based amplifiers to generate the output power of a few 100s of watts in X-band. The heat generated of around 200W is transferred from the GaN devices to the liquid-cooled system through the thin narrow edge contact (35mm) of the power amplifier. The power negative-positive-negative (NPN) Darlington transistor is used to source high current required for the high power GaN devices. The standard low voltage series regulator in combination with shunt regulator adapted to generate the regulated output voltage required for drain pulsing circuits of the GaN amplifiers. The shunt regulator enables to adjust the drain voltages of the GaN devices which in turn may enable to adjust the output power generated from these GaN devices.
[0019] The drain pulsing circuits use high-speed P-channel MOSFETs with low input, output resistance and capacitance to ensure a fast rise and fall time of <50ns. This enables the amplifier to generate very low pulse width e.g., 250ns drain voltages that are required for the GaN devices. The cut-off circuits is used to prevent the pulsed power amplifier from entering in longer pulse width and high duty operations and hence increasing the reliability of the GaN devices. The design of the pulsed power amplifier is such that the other heat-generating components are placed diagonally opposite to and away from the heat-generating GaN devices, hence providing a uniform thermal gradient. Temperature shut down override facility provided to operate the system during an emergency for a short duration.
[0020] In an aspect, the present disclosure relates to an apparatus with integrated control, the apparatus comprising a housing with a narrow contact edge, one or more power amplifiers are optimally placed closer to the narrow contact edge of the housing, low RF input is received from an exciter unit and provide the sufficient gain in different stages to generate high RF output power over an operational frequency band. The different stages comprise a pre-driver stage, driver stage and high-power stages, the high-power stages comprise one or more power amplifiers, where the one or more power amplifiers coupled to a combiner to combine the power from the one or more power amplifiers, wherein the one or more power amplifiers are Gallium nitride (GaN) amplifiers. A high voltage medium current regulatory circuit configured in the apparatus, the high voltage medium current regulatory circuit adapted to adjust the regulated output voltage and implemented to adjust the final output power for the one or more power amplifiers, wherein heat generated from the one or more power amplifiers is transferred to a liquid-cooled system through the narrow contact edge.
[0021] According to an embodiment, the one or more power amplifiers are optimally placed closer to the narrow contact edge of the housing, which is in direct contact to a cold plate such that heat is transferred from the junction of the one or more power amplifiers to the liquid cooling system.
[0022] According to an embodiment, the high voltage medium current regulatory circuit comprise a shunt regulator, a standard low voltage series regulator and a power NPN Darlington transistor, where a combination of the series regulator and shunt regulator are used with adjustable feature for better ripple reduction and to provide regulated direct current (DC) voltage output for the one or more power amplifiers to adjust the final output power for the one or more power amplifiers.
[0023] According to an embodiment, the apparatus comprises a drain pulsing circuit adapted to generate pulsed voltage, the drain pulsing circuit comprises high-speed P-channel metal–oxide–semiconductor field-effect transistor (MOSFETs) having low internal input resistance, output resistance and capacitance to ensure a fast rise and fall time for the pulsed final output power.
[0024] According to an embodiment, the apparatus comprises a monitor and control card that comprises a FPGA that monitors the health of the apparatus and reports the status through a monitor and control interface using low voltage differential signaling (LVDS) lines and to cut-off the drain voltages of the one or more power amplifiers from entering in longer pulse width and high duty operations, thereby increasing the reliability of the one or more power amplifiers.
[0025] According to an embodiment, the apparatus comprises a temperature-sensing circuitry that monitors the unit’s temperature to generate alarms and trips off the one or more power amplifiers in case of extreme over-heating, wherein temperature-sensing circuitry enables the one or more power amplifiers to operate in high temperature emergency with settable threshold temperature.
[0026] Various objects, features, aspects, and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments, along with the accompanying drawing figures in which like numerals represent like components.

BRIEF DESCRIPTION OF THE DRAWINGS
[0027] The following drawings form part of the present specification and are included to further illustrate aspects of the present disclosure. The disclosure may be better understood by reference to the drawings in combination with the detailed description of the specific embodiments presented herein.
[0028] FIG. 1 illustrates an exemplary view of X-Band GaN based pulsed power amplifier, in accordance with an embodiment of the present disclosure.
[0029] FIG. 2A illustrates an exemplary front side of mechanical arrangement of the pulsed power amplifier, in accordance with an embodiment of the present disclosure.
[0030] FIG. 2B illustrates an exemplary rear side of mechanical arrangement of the pulsed power amplifier, in accordance with an embodiment of the present disclosure.
[0031] FIG. 3A illustrates a graphical view of measured output power for narrow pulse width, in accordance with an embodiment of the present disclosure.
[0032] FIG. 3B illustrates a graphical view of measured output power for wide pulsed width, in accordance with an embodiment of the present disclosure.
[0033] FIG. 4 illustrates a schematic view of thermal imager data on cold plate, in accordance with an embodiment of the present disclosure.
[0034] FIG. 5 illustrates a flow diagram of a method of operating an apparatus, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION
[0035] The following is a detailed description of embodiments of the disclosure depicted in the accompanying drawings. The embodiments are in such detail as to clearly communicate the disclosure. If the specification states a component or feature “may”, “can”, “could”, or “might” be included or have a characteristic, that particular component or feature is not required to be included or have the characteristic.
[0036] As used in the description herein and throughout the claims that follow, the meaning of “a,” “an,” and “the” includes plural reference unless the context clearly dictates otherwise. Also, as used in the description herein, the meaning of “in” includes “in” and “on” unless the context clearly dictates otherwise.
[0037] The present disclosure relates, in general, to pulsed Radar systems, and more specifically, relates to a liquid-cooled solid-state pulsed power amplifier with an integrated control system. The present disclosure relates to a method of design of a liquid-cooled solid-state GaN-based pulsed power amplifier with an integrated control system. The power amplifier receives the low RF input from an exciter unit and provides sufficient gain in different stages to give the high output RF power over the operational frequency band. It can transfer the heat generated around 200W from the GaN devices to the liquid-cooled system through the thin narrow edge contact of the power amplifier. It can work for narrow pulse 100ns to wide pulse 25µs.
[0038] A high voltage medium-current linear regulator circuitry consisting of a series regulator and a shunt regulator with a provision for adjusting the regulated output voltage and implemented to adjust the final output power. The proposed pulsed power amplifier includes FPGA based monitor and control (M&C) card for achieving 100Mbps communication with radar controller using low voltage differential signalling (LVDS) lines. The developed module has a special feature called temperature shut down override. In the usual operation of the module if the temperature exceeds an allowed temperature the power amplifier shuts down and reports the issue to the radar controller (RC). The present disclosure can be described in enabling detail in the following examples, which may represent more than one embodiment of the present disclosure.
[0039] The advantages achieved by the pulsed power amplifier of the present disclosure can be clear from the embodiments provided herein. The description of terms and features related to the present disclosure shall be clear from the embodiments that are illustrated and described; however, the invention is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents of the embodiments are possible within the scope of the present disclosure. Additionally, the invention can include other embodiments that are within the scope of the claims but are not described in detail with respect to the following description.
[0040] FIG. 1 illustrates an exemplary view of X-Band GaN based pulsed power amplifier, in accordance with an embodiment of the present disclosure.
[0041] Referring to FIG. 1, pulsed power amplifier 100 (also referred to as an apparatus 100, herein) provided with an integrated control system, where heat generated from the pulsed power amplifier 100 is transferred through a narrow edge contact of mechanical housing 202 shown in FIG. 2A to a liquid-cooled system external to the apparatus 100. The pulsed power amplifier 100 can include coupler 102, detectors (104-1 to 104-3), monitor and control card 106, an isolator (108-1,108-2), circulator 108-3, pre-driver stage 110, driver stage 112 and high-power stages (114-1, 114-2), power divider 116-1, combiner 116-2, first output coupler 118-1, second output coupler 118-2, electromagnetic interference (EMI) filter 120, direct current (DC)-DC converter 122, high-voltage and medium current regulatory circuits 124, pulsing circuit 128, temperature-sensing circuitry 130, low voltage DC bias 132 and RF 50ohm terminations 134.
[0042] In an exemplary embodiment, the pulsed power amplifier 100 as presented in the example is a solid-state Gallium Nitride (GaN) based pulsed power amplifier. The pulsed power amplifier 100 adapted to receive pulsed radio frequency (RF) input at a predefined frequency e.g., X-band. The pulsed power amplifier 100 receives the low RF input from an exciter unit and provide sufficient gain in different stages i.e., three stages to give the high output RF power over an operational frequency band. A sample of the RF input is coupled through the coupler 102 and is converted to direct current (DC) by the detector 104-1 and is sent to the monitor and control card 106 for input power status report. The isolator 108-1 coupled to the coupler 102 and can be used at the input to provide a better match at the input terminal. The pulsed power amplifier 100 may be designed in three stages viz. pre-driver stage 110, driver stage 112 and high-power stages (114-1, 114-2). In an exemplary embodiment, the low-power RF amplification is achieved using Gallium Arsenide (GaAs) technology while the high-power RF amplification is achieved using Gallium Nitride (GaN) technology.
[0043] The hybrid quadrature coupler-based power divider 116-1 and combiner 116-2 are coupled to the high-power stages (114-1, 114-2). The combiner 116-2 adapted to combine the power from the high-power stages (114-1, 114-2), where the high-power stages (114-1, 114-2) can include one or more power amplifiers (114-1, 114-2) (also referred to as power amplifiers, herein). In an exemplary embodiment, one or more power amplifiers (114-1, 114-2) can include at least two GaN devices. The sample of output power from the power combiner 116-2 is taken through the first output coupler 118-1 to the detector 104-2 and is converted to DC to give forward power status. The circulator 108-3 is used to minimize the load reflections.
[0044] At the third port of circulator 108-3, the reflected energy is coupled through the second output coupler 118-2 and is finally detected by the detector 104-3 to give reflected power status, adequate voltage standing wave ratio (VSWR) protection is provided by monitoring this reflected power and issuing a cut-off control to the GaN devices during high reflections.
[0045] In an exemplary embodiment, the isolator (108-1, 108-2) can be low power isolators and circulator 108-3 can be high power circulator. In another exemplary embodiment, the first output coupler 118-1 is employed for forward power detection and the second output coupler 118-2 for reverse power detection. In another exemplary embodiment, the detectors (104-1 to 104-3), are RF input power level detector 104-1, RF forward power level detector 104-2 and RF reverse power level detector 104-3.
[0046] The pulsed power amplifier 100 operates at a DC voltage (V1) and internally generates all the voltages required for the power amplifiers (also interchangeably referred to as RF devices) in the appropriate sequence. The DC input features are reverse-polarity protection, transient-suppression, and EMI filtering performed by the EMI filter 120. Using DC-DC converter 122, the prime voltage V1 is converted into V2 VDC which needs to be pulsed for the operation of the GaN devices (114-1, 114-2). The V2 voltage is regulated using high-voltage and medium current regulatory circuits 124. These circuits have a provision for adjusting the regulated output voltage with optimal efficiency.
[0047] The high-voltage and medium current regulatory circuits 124 can include shunt regulator 126-1, standard low voltage series regulator 126-2, variable resistor 126-4 and power NPN Darlington transistor 126-3. The power NPN Darlington transistor 126-3 is used to provide high current gain. A combination of the series regulator 126-2 and shunt regulator 126-1 are used with the adjustable feature for better ripple reduction and to provide regulated DC voltage output for the GaN amplifiers/devices to adjust the final output power for the power amplifiers (114-1, 114-2). The ground reference of the series regulator 126-2 is shifted using the shunt regulator 126-1. The voltage across the shunt regulator 126-1 can be adjusted using the variable resistor 126-4, which allows to adjust the regulated voltage. This voltage later gets pulsed using the drain pulsing circuit 128.
[0048] The drain pulsing circuit 128 is adapted to generate pulsed voltage and uses high-speed P-channel MOSFETs, which have very low internal input resistance, output resistance and capacitance. This ensures fast rise and fall time e.g., <50ns for the pulsed V2 voltage, which further enables the GaN devices (114-1, 114-2) to generate narrow drain pulses with pulse widths of the order of 250ns that are required for the GaN devices.
[0049] Provision of adjusting the drain voltage enables to adjust the final RF output powers, hence achieving RF power adjustment using DC circuits without compromising system efficiency and disturbing any RF circuits. In this power amplifier, drain voltage switching is used for GaN devices in place of gate voltage switching to overcome the issue of possible device instability and to ensure better reliability.
[0050] The monitor and control card 106 is realized using low power, integrated field-programmable gate array. (FPGA)/microcontroller with built-in peripheral interfaces. The monitor and control card 106 monitors the health of the pulsed power amplifier 100 and reports the status through the monitoring and control interface at a data rate of 100MBps using low voltage differential signaling (LVDS) lines. The monitor and control card 106 also prevent the pulsed power amplifier 100 from entering in longer pulse width and high duty operations, thereby increasing the reliability of the GaN devices.
[0051] The proposed pulsed power amplifier 100 can include a special feature called temperature shut down override. The temperature-sensing circuitry 130 monitors the unit’s temperature to generate alarms and trips off the power amplifier in case of extreme overheating. In the usual operation of the module if the temperature exceeds an allowed temperature, the power amplifier shuts down and reports the issue to the radar controller (RC). However, during the issue of temperature shut down override command from radar controller, the PA may continue to operate till the max temperature limit is reached and then switches off. This feature can enable to operate the system during an emergency for a short duration. Tricolour light-emitting diodes (LEDs) are provided to visually indicate ‘Power On’ and summary faults.
[0052] FIG. 2A illustrates an exemplary front side of mechanical arrangement 200 of the pulsed power amplifier, in accordance with an embodiment of the present disclosure.
[0053] The pulsed power amplifier 100 can include the housing 202 that is a milled part from a block preferably made of aluminium material with the narrow contact edge of 35mm. The GaN devices (114-1, 114-2) are optimally placed closer to the narrow contact edge of the mechanical housing 202 which is in direct contact with a cold plate in order to achieve quick and maximum heat transfer from the junction of the GaN devices to the liquid-cooling system (also interchangeably referred to as an external cooling system). The surface finish of <2µm is maintained at places, where the GaN PA devices are mounted at the external narrow thin edge of the pulsed power amplifier 100, which is in contact with the cold plate.
[0054] The heat generated from the power amplifiers is transferred to the liquid-cooled system through the narrow contact edge. For example, it can transfer the heat generated around 200W from the GaN devices to the liquid-cooled system through the thin narrow edge around 35 mm wide contact of the power amplifier.
[0055] As seen from the FIG. 2A, the design of the PPA is such that the other heat-generating components like DC-DC converters 122 are placed diagonally opposite to and away from the heat-generating GaN PA devices (114-1, 114-2), hence providing a uniform thermal gradient. The chassis temperature-sensing circuitry 130 monitors the unit’s temperature to generate alarms and trips off the amplifier in case of extreme overheating.
[0056] FIG. 2B illustrates an exemplary rear side of mechanical arrangement of the pulsed power amplifier, in accordance with an embodiment of the present disclosure. As shown in FIG. 2B, the monitor and control card can include the microcontroller/FPGA based circuitry to cut off the drain voltages of the one or more power amplifiers from entering in longer pulse width and high duty operations, thereby increasing the reliability of the one or more power amplifiers. For example, internal supply to GaN PA devices gets cut-off, if the external cover pulse exceeds higher limit of pulse width, thereby preventing the pulsed power amplifier from entering in long pulse width operations of 25µsec.
[0057] FIG. 3A illustrates a graphical view 300 of measured output power for narrow pulse width, in accordance with an embodiment of the present disclosure. The RF output power of the pulsed power amplifier 100 for narrow pulse width of 100ns operation is shown in FIG. 3A.
[0058] FIG. 3B illustrates a graphical view of measured output power for wide pulsed width, in accordance with an embodiment of the present disclosure. The RF output power of the pulsed power amplifier 100 for wide pulsed width of 25µs is shown in FIG. 3B.
[0059] FIG. 4 illustrates a schematic view 400 of thermal imager data on cold plate, in accordance with an embodiment of the present disclosure. FIG. 4 depicts the actual thermal profile data taken for the amplifier when PA is in full load operation on the cold plate.
[0060] The embodiments of the present disclosure described above provide several advantages. The present disclosure provides apparatus 100 that combines power from high power amplifiers to generate the higher output power. The apparatus 100 transfers heat generated from the power amplifiers to the liquid-cooled system. The apparatus enables to adjust the drain voltages of the power amplifiers which in turn may enable to adjust the output power generated from these power amplifiers. The apparatus ensures fast rise and fall time to enable the amplifier to generate a very low pulse width.
[0061] The present disclosure provides the apparatus that prevents the pulsed power amplifier from entering in longer pulse width and high duty operations and hence increasing the reliability of the power amplifiers. The apparatus provides a uniform thermal gradient, achieves narrow pulse width application and is operated during an emergency for a short duration.
[0062] FIG. 5 illustrates a flow diagram of a method of operating an apparatus, in accordance with an embodiment of the present disclosure.
[0063] Referring to FIG. 5, the method 500 includes a block 502, the housing with the narrow contact edge, where the one or more power amplifiers configured in the apparatus are optimally placed closer to the narrow contact edge of the housing. The low RF input is received from the exciter unit and provide the sufficient gain in different stages to generate high RF output power over an operational frequency band.
[0064] At block 504, the high voltage medium current regulatory circuit configured in the apparatus, the high voltage medium current regulatory circuit adapted to adjust the regulated output voltage and implemented to adjust the final output power for the one or more power amplifiers, where heat generated from the one or more power amplifiers is transferred to the liquid cooled system through the narrow contact edge.
[0065] It will be apparent to those skilled in the art that the apparatus 100 of the disclosure may be provided using some or all of the mentioned features and components without departing from the scope of the present disclosure. While various embodiments of the present disclosure have been illustrated and described herein, it will be clear that the disclosure is not limited to these embodiments only. Numerous modifications, changes, variations, substitutions, and equivalents will be apparent to those skilled in the art, without departing from the spirit and scope of the disclosure, as described in the claims.

ADVANTAGES OF THE PRESENT DISCLOSURE
[0066] The present disclosure provides an apparatus that combines power from high power amplifiers to generate the output power effectively.
[0067] The present disclosure provides an apparatus that transfers heat generated from the power amplifiers to a liquid-cooled system.
[0068] The present disclosure provides an apparatus that enables to adjust the drain voltages of the power amplifiers which in turn may enable to adjust the output power generated from these power amplifiers.
[0069] The present disclosure provides an apparatus that ensures fast rise and fall time to enable the amplifier to generate a very low pulse width.
[0070] The present disclosure provides an apparatus that prevents the pulsed power amplifier from entering in longer pulse width and high duty operations and hence increasing the reliability of the power amplifiers
[0071] The present disclosure provides an apparatus that provides a uniform thermal gradient.
[0072] The present disclosure provides an apparatus with temperature shut down override facility which enables the apparatus to operate during an emergency for a short duration.