K-band Frequency Components

Down converter is an essential part in the microwave integrated circuits receiving system. Whether in use of microwave communications, radar, remote control and sensor, or detecting and electronic confrontation, and many microwave measuring system, we need to convert the microwave signals down to lower frequency to be processed.The work of this paper is manufacturing a down-conversion module which can convert the K-band microwave signals to X-band. The module is a part of a high-speed data transmission system, so the spurious suppression, convert gain and band flatness are required. The local oscillator source are integrated in the module, it requires good performance of phase-noise.At first, we introduced the development of down-converter system and its application. Then we analyse the user's index and decide the method to achieve the module. A phase-lock loop frequency synthesizer and multipliers are used to achieve the local oscillator source. High-order multiplication contains several frequency doublers and band-pass filters are used to suppress the harmonics. In order to achieve the required output power, we put three amplifiers in the output circuit. The spurious suppression is relied on two filters. A balancer is used to achieve the requirement of the gain flatness. According to the demond of the circuit, we designed three band-pass filters with two different structures and one balancer by using ADS and HFSS.The measurement results shows that the output P1dB achieves 5dBm, spurious suppression is better than 60dBc, convert gain flatness in band is less than 3dB. The down-convert module has a good performance.