Variable Frequency Systems On The Miniaturization Of Broadband S-band

In modern microwave communication system, the transmitter occupies a pivotal position. The upconverter which has superior performance plays a key role to improve the transmitter system indicators. This paper studies a broadband, low spurious, low phase noise S-band up conversion system, which is used to shift the spectrum of140MHz signal to2.4-4GHz without distortion.First the paper makes a brief introduction about the development of domestic microwave upconversion system. In accordance with requirements of the system, we make a detail analysis, finally select double conversion superheterodyne architecture to implement the up conversion system. We use Genesys software to conduct mixer intermodulation distributed simulation, considering the low spurious claims and the difficulty of designing the filter, then select the best IF frequency and determine overall system solution. In the process of specific design uses Protel, By using ADIsimPLL to do Phase-locked loop simulation we determine the optimal loop bandwidth. We make the Simulation of the filter with ADS to verify the reliability of the system, and use Protel, Solidworks to design the circuit schematic, layout and cavity structure. Finally we can achieve the miniaturization of broadband S-band frequency conversion system.The test results:in the output bandwidth2.4-4GHz of the up conversion system, spurious suppression is greater than60dBc, flatness is less than4dB, and phase noise is less than-80dBc/Hz@10kHz. Each performance indicator meets the system requirements. At last the paper also analyzes the various issues that arise in the actual design and debugging, and gives a solution.