Measurement Technique Research And Realization Of Mixer Chip

Mixer is one of the most important blocks in RF transceiver; mixer is used to make frequency transformation. The research about mixer design is very common is thesis, but the research about mixer measurement is hardly to find in homeland. Because the limitation of measuring scheme, test equipment, it is difficult to complete mixer test measurement. What's more, owe to lack of experience, the measuring result is often not accurate enough. So, it is necessary to study how to measure the mixer all round.In this paper, firstly introduce the basic theory of mixer, including principle, structure and specification. Then, summary the measure methods about the port impedance, Gain, linearity and noise figure. After that, list the tips in RF test board design, such as decoupling, grounding etc. Based on the mixer chip ADL5801 form TI, finish the test schematic and realize the test board in Allegro.When complete test board soldering, different measuring platform is built up in laboratory according to different item. The measuring results shows when RF input frequency is 900 MHz, 1900 MHz, 2500 MHz and 3500 MHz, with fixed 153 MHz Intermediate Frequency. The conversion gain is 1.78 dB, 1.76 dB,-0.159 dB,-0.722 dB respectively. The P1 dB is 12.64 dBm, 12.5dBm, 12.5dBm, 11.26 dBm respectively. The IP3 is 28.24 d Bm, 24.16 dBm, 22.11 dBm, 17.17 dBm respectively. The NF is 9.75 dB, 11.21 dB, 12.51 dB, 16.78 dB respectively. Finally the measuring results are compared to reference and make some illustration. It is show that the methods about mixer test in this paper are suitable. In the end of the paper, further work is put forward.