Supply-Modulated Radar Transmitters With Amplitude-Modulated Pulses
| Autor: | Andrew Zai, Zoya Popovic, Mauricio Pinto, Mike Coffey |
|---|---|
| Rok vydání: | 2015 |
| Předmět: |
Pulse repetition frequency
Physics Pulse-frequency modulation Radiation business.industry Amplifier Pulse duration Condensed Matter Physics Amplitude modulation Optics Pulse compression Pulse-amplitude modulation Electronic engineering Electrical and Electronic Engineering business Bandwidth-limited pulse |
| Zdroj: | IEEE Transactions on Microwave Theory and Techniques. 63:2953-2964 |
| ISSN: | 1557-9670 0018-9480 |
| DOI: | 10.1109/tmtt.2015.2450747 |
| Popis: | This paper introduces an efficient radar transmitter with improved spectral confinement, enabled by a pulse waveform that contains both amplitude and frequency modulation. The theoretical behavior of the Class-B power amplifier (PA) under a Gaussian envelope is compared to that of a Class-A PA. Experimental validation is performed on a 4-W 10-GHz GaN monolithic microwave integrated circuit PA, biased in Class B with a power-added efficiency (PAE) of 50%. When driven with a Gaussian-like pulse envelope with a 5-MHz linear frequency modulation (LFM), the PA demonstrates a 31% average efficiency over the pulse duration. To improve the efficiency, a simple resonant supply modulator with a peak efficiency of 92% is used for the pulse Gaussian amplitude modulation, supplemented by pre-distortion on the PA input, while the LFM is provided through the PA input. This case results in a five-point improvement in system efficiency with an average ${\rm PAE}=40\hbox{\%}$ over the pulse duration for the PA alone, and with simultaneous 40-dB reduction in spectral emissions relative to a rectangular pulse with the same energy. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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