Field of the invention
The present invention mainly relates to solid state pulse power amplifier and more particularly to a lateral diffused metal oxide semi-conductor Field Effect Transistor (LDMOSFET) based high power Solid State Pulse Power Amplifier.
Background of the invention
With the rapid development of electronic technology, the automotive and military EMC radiated immunity susceptibility testing, as well as radar and communication applications uses solid state pulse power amplifiers. Com pared with other amplifiers, the solid state pulse power amplifiers are operate with output power levels up to 1,000 watts and frequencies to more than 18 GHz.
These power amplifiers serve as cost-effective replacements for traveling wave tube (TWT) amplifiers and offer longer life, better efficiencies, small size, light weight, high reliability and other characteristics favoured, has been very widely used among mobile communications, interference identification RF / microwave systems, radar communications, military securities and it accounts for a very important position.
One of the prior art CN204258737 U discloses an L-waveband high-power amplifier based on an LDMOS. The L-waveband high-power amplifier based on the LDMOS comprises an impedance traction switch connected with a frequency synthesizer, wherein the impedance traction switch is connected with a primary

amplifier, a first impedance transformation section, a first capacitor, a secondary amplifier, a second impedance transformation section and a second capacitor in sequence, and the second capacitor is connected with an antenna. The L-waveband high-power amplifier based on the LDMOS overcomes the defects that an existing L-waveband power amplifier needs multi-level boosting and is high in debugging difficulty. The L-waveband high-power amplifier based on the LDMOS is easy to debug, good in environmental adaptability, high in power, centralized in frequency spectrum, small in out-of-band clutter and free of interference to communication between adjacent channels.
Another prior art CN103905004 A discloses an RF power amplifying system for navigation ranging. The RF power amplifying system amplifies a 5 dBm input pulse signal to 500W and is used for calibrating the ranging function of short-range navigation detection equipment. The RF power amplifying system comprises an input isolator, a high-power RF amplifier, a circulator, an output isolator, an amplitude limiter, a power source and an RF switch. The RF power amplifying system for navigation ranging has the advantages of being high in power, excellent in stability and reliability and applicable to a TACAN simulator and a microwave landing system.
Further prior art CN 202551012 U discloses an L-wave-band solid-state transmitter. The L-wave-band solid-state transmitter has an operating frequency L1 wave band of 1227.6MHz+/-10MHz and an operating frequency L2 wave band of 1575.42MHz+/-10MHz, and comprises an input coupler, a band-pass filter, a pre-class power amplifier module, a distributor, a plurality of final power amplifier

modules, a synthesizer, a coupler, a detector and a central processing unit (CPU) controller, wherein the input coupler is connected with the band-pass filter and the CPU controller, the band-pass filter is connected with the pre-class power amplifier module, the output of the pre-class power amplifier module is connected with the distributor, the plurality of final power amplifier modules are respectively connected with the distributor and the synthesizer, the output of the synthesizer is connected with the coupler, a coupling end of the coupler is connected with the detector, the detector is connected with the CPU controller, the CPU controller is connected with the pre-class power amplifier module, and the CPU controller is also connected with display screen and panel keys and a communication serial port. The L-wave-band solid-state transmitter is reasonable in design, high in efficiency and high in reliability.
Summary of the Invention
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.
Accordingly, in one aspect of the present invention relates to a solid state pulse power amplifier, the amplifier comprising: a main housing, wherein the main housing encloses RF part and DC parts, where the RF part is positioned in the middle portion of the main housing and the DC parts positioned on the either side of the main housing through partition plates, the RF part comprising: a first 2way 90

degree hybrid coupler module receives a pulsed RF signal as input, wherein the pulsed RF signal is split into two output signals by 2way 90 degree hybrid coupler module, at least two power amplifier to receive the output pulsed signal from the first hybrid coupler module with a gain of 16dB and output of 700Wpeak operating over the full band and a second 2way 90 degree hybrid coupler module is to receive the outputs from at least two power amplifiers, wherein the second hybrid coupler modulecombines the received outputs to get output of 1.2KW.
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 the drawings
The above and other aspects, features, and advantages of certain exemplary embodiments of the present invention will be more apparent from the following description taken in conjunction with the accompanying drawings in which:
Figure 1 shows the top-level functional block diagram and inside view of solid state power pulse amplifier according to one embodiment of the present invention.
Figure 2 shows the graph showing plot of Frequency v/s Power output in dBm according to one embodiment of the present invention.
Figure 3 shows the graph showing plot of Frequency v/s Power output in Watts

according to one embodiment of the present invention.
Figure 4shows the table showing test results of power amplifier according to one embodiment of the present invention.
Persons skilled in the art will appreciate that elements in the figures are illustrated for simplicity and clarity and may have not been drawn to scale. For example, the dimensions of some of the elements in the figure may be exaggerated relative to other elements to help to improve understanding of various exemplary embodiments of the present disclosure. Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
Detailed description of the invention
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.
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.
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.
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 is intended to provide.
Figs. 1 through 4, 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.
The present invention relates to design of 1.2KW L band Solid State Pulse Power Amplifier using LDMOSFET devices by combining two of 700W each Power Amplifier in compact size. The present invention "Solid state pulse power amplifier" operates over highest pulse width of 150us with low rise time /fall time which is below 30ns. Further, the RF PCBs are vapor phase soldered to nickel plated aluminum base plate for good electrical grounding. Input and output RF tracks are joined with copper foils to avoid connectors which reduced size. The SSPA is water cooled for good thermal management.
The present invention provides a wideband RF power amplifier system, the input pulse signal amplification 46dBm to 1.2KW in frequency band of 1.25 to 1.35GHz with high pulse width of 150us and low rise/fall time below 30ns for RADAR with protections.
Figure 1 shows the top-level functional block diagram and inside view of solid state power pulse amplifier according to one embodiment of the present invention.
The figure shows the top-level functional block diagram and inside view of solid state power pulse amplifier 100. The solid state power pulse amplifier comprises a

main housing 110, RF part 120 and a DC part 130. The main housing110 encloses RF part 120 and DC parts 130, where the RF part is positioned in the middle portion of the main housing and the DC parts positioned on the either side of the main housing through partition plates. The RF parts further comprises a first 2way 90 degree hybrid coupler module 122, at least two power amplifier 124, and a second 2way 90 degree hybrid coupler module 126. The first 2way 90 degree hybrid coupler module receives a pulsed RF signal as input, where the pulsed RF signal is split into two output signals by 2way 90 degree hybrid coupler module. The at least two power amplifier is to receive the output pulsed signal from the first hybrid coupler module with a gain of 16dB and output of 700Wpeak operating over the full band. The second 2way 90 degree hybrid coupler module is to receive the outputs from at least two power amplifiers, wherein the second hybrid coupler module combines the received outputs to get output of 1.2KW.
The solid state power amplifier receives pulsed RF input of 46dBm in the frequency range of 1.25-1.35GHz from previous splitter stage. The input is split into two by first 2way 90 deg hybrid coupler module IPP2307 (4.5KW/450W). The first 2way 90 degree hybrid coupler module IPP2307 (4.5KW/450W) has termination of 60W in hybrid coupler termination port. The output from the first 2way 90 degree hybrid coupler module is fed to at least two 700W Basic Power Amplifier stage using device PTVA127002EV from Infineon with a gain of 16dB and output of 700Wpeak operating over the full band. Both PA modules receives all bias and supply through each BPA Bias card which has provision for storage capacitors, in-

rush current protection, current sensing and thermal sensor. The outputs of both Power Amplifiers are combined using second 2way 90 degree Hybrid couplers IPP2307 (4.5KW/450W) to get output of 1.2KW. Termination of 250W is used in hybrid coupler termination port. This method protects power devices from failing due to output open/short as the reflected power goes to termination port.
The present invention "solid state pulse power amplifier" further comprises a thermal switch which is mounted on each (PA) power amplifier chassis. It gives thermal fault signal in case temperature exceeds +85 deg C. Module receives 50V DC supply, PA Bias ON/OFF cover pulse. Over current protection, in-rush current protection is provided. Storage capacitors are calculated based on highest pulse width and droop parameters.
The RF PCBs are vapor phase soldered to nickel plated aluminum base plate for good electrical grounding. Input and output RF tracks are joined with copper foils to avoid connectors which reduced size. The present invention provides an wideband RF power amplifier system, the input pulse signal amplification 46dBm to 1.2KW in frequency band of 1.25 to 1.35GHz with high pulse width of 150us & low rise/fall time below 30ns for RADAR with protections.
Figure 2 shows the graph showing plot of Frequency v/s Power output in dBm according to one embodiment of the present invention. The figure shows the graph plotted between the frequency and the Power output in dBm.
Figure 3 shows the graph showing plot of Frequency v/s Power output in Watts

according to one embodiment of the present invention. The figure shows the graph plotted between the frequency and the Power output in watts.
Figure 4shows the table showing test results of power amplifier according to one embodiment of the present invention.
The table below shows the test results of solid state pulse power amplifier.

Those skilled in this technology can make various alterations and

modifications without departing from the scope and spirit of the invention. Therefore, the scope of the invention shall be defined and protected by the following claims and their equivalents.
FIGS. 1-4 are merely representational and are not drawn to scale. Certain portions thereof may be exaggerated, while others may be minimized. FIGS. 1-4 illustrate various embodiments of the invention that can be understood and appropriately carried out by those of ordinary skill in the art.
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.
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.

We claim:
1. A solid state pulse power amplifier, the amplifier comprising:
a main housing, wherein the main housing encloses RF part and DC parts, where the RF part is positioned in the middle portion of the main housing and the DC parts positioned on the either side of the main housing through partition plates;
the RF part comprising:
a first 2way 90 degree hybrid coupler module receives a pulsed RF signal as input, wherein the pulsed RF signal is split into two output signals by 2way 90 degree hybrid coupler module;
at least two power amplifier to receive the output pulsed signal from the first hybrid coupler module with a gain of 16dB and output of 700Wpeak operating over the full band; and
a second 2way 90 degree hybrid coupler module is to receive the outputs from at least two power amplifiers, wherein the second hybrid coupler module combines the received outputs to get output of 1.2KW.
2. The amplifier as claimed in claim 1, wherein the output from the first 2way 90

degree hybrid coupler module is fed to at least two 700W Basic Power Amplifier stage using device PTVA127002EV from Infineon with a gain of 16dB and output of 700Wpeak operating over the full band.
3. The amplifier as claimed in claim 1, wherein the first 2way 90 degree hybrid coupler module IPP2307 (4.5KW/450W) has termination of 60W in hybrid coupler termination port.
4. The amplifier as claimed in claim 1, wherein at least two (PA) power amplifier modules receives all bias and supply through each (BPA)basic power amplifier Bias card has provision for storage capacitors, in-rush current protection, current sensing and thermal sensor.
5. The amplifier as claimed in claim 1, wherein the second 2way 90 degree hybrid coupler modulelPP2307 (4.5KW/450W) has termination of 250W in hybrid coupler termination port.
6. The amplifier as claimed in claim 1, wherein the termination method protects power devices from failing due to output open/short as the reflected power goes to termination port.

7. The amplifier as claimed in claim 1, wherein the amplifier further comprising thermal switch mounted on each PA chassis which gives thermal fault signal in case temperature exceeds +85 deg C.
8. The amplifier as claimed in claim 1, wherein the RF PCBs are vapor phase soldered to nickel plated aluminum base plate for good electrical grounding and further the Input and output RF tracks is joined with copper foils to avoid connectors which reduced size.
9. The amplifier as claimed in claim 1, wherein the solid state power amplifier amplifies pulsed RF input of 46dBm in the frequency range of 1.25-1.35GHz to 1.2KW with high pulse width up to 150us and rise time/fall time below 30ns for RADAR with protections.