Microwave Band Low-power Comb Spectrum Generator Developed

Comb generators have a very wide range of applications in the modern microwave systems. Because of its multiplier effect it can be easily made of millimeter-wave frequency sources. It is also the key devices or instruments for the expansion of frequency bandwidth and frequently used in microwave communications, EMC testing, microwave electronic warfare and so on.The article starts with the elements of frequency multiplier, analyses the circuit structure of generating the comb spectrum, the computing of the circuit parameters for different parts, the choice of generator's core device——step recovery diode (SRD), the input and output matching for generator's circuit and self-bias settings and so on. At the same time due to the system power requirement, designing a driving power amplifier is in need. In the article the theory and design methods for power amplifiers are also introduced. Finally the design has selected a step recovery diode of Metelics Corporation and power tubes of Sirenza Corporation. The design of comb generator which is from 0.2GHz to 18GHz is successful. Via testing the power level is greater than -30dBm at the highest output signal. And compared to similar products abroad, in the case of low-cost, the same output power has been received and power consumption is similar to foreign products.