High Power S-band Broadband Sweep Noise Source

RF thermal (white) noise sources have many useful applications in communication field, which solve a myriad of engineering problems everyday. The main research activities are as the following:1. Instead of expensive commercially available white noise generators, we developed a new type of circuit which is an inexpensive version that produces frequencies up to several hundreds MHz. Its operation is based on the noise generated by the Zener breakdown phenomenon in the BJT inversely polarized base-collector junction.2. We designed a C-band phase-locked loop frequency synthesizer. The range of frequency is from 4GHz to 5GHz, the channel spacing is 2 to 10MHz adjustable, the output power is about +10dBm.3. We designed and fabricated two types of bandpass filters (BPF). One is a C-band Microstrip narrowband BPF with passband from 6.4 GHz to 6.6 GHz, and the other one is an S-band Microstrip wideband BPF with passband from 1.5 GHz to 2.5 GHz. Also, we measured their performance in experiment and the results are nearly consistent with the simulated results. The design requirements have been satisfied.4. In order to control the system, we have designed and fabricated a control module based on Texas Instruments'MSP430 MCU, which can control frequency, channel spacing, power, VSWR, temperature, and so on.