Reseach On Frequency Extension Module Of Antenna Measurement System

The working frequency of antenna is becoming more and more higher with the development of microwave technology to the millimeter wave and Sub-millimeter wave frequency. Accordingly, it makes a new challenge for antenna measurement. Millimeter wave antenna measurement system is mainly composed of antenna measurement system in lower frequency range by frequency extension. So, it is a significance thing that researching the millimeter wave frequency extension module.Firstly, this paper made a brief analysis of the mainstream antenna measurement system. Then According to the actual condition of the laboratory, a set of antenna measurement system based on spectrum analyzer is designed. Second, in order to measurement millimeter wave antenna, by use of microwave millimeter wave frequency extension technology, a series of frequency multiplier and mixer components were developed to make the antenna measurement frequency range extend to millimeter wave even Sub-millimeter wave frequency. The paper makes a deep research on frequency multiplier and harmonic mixer. Then the design, fabrication and testing of Ka-band frequency Doubler and W-band Fourth Harmonic Mixer is discussed mainly in this paper. The measured results show that the output power of the frequency doubler is more than 15 dBm in the 26.5 to 40 GHz band. The frequency conversion loss of the Fourth Harmonic Mixer is less than 23 dB in the 84 to 89 GHz band.and less than 33 dB in the 84 to 98 GHz band. The Fourth Harmonic Mixer satisfies the requirement of the laboratory millimeter wave antenna measurement system in W band wider frequency range. There are series of advantages with antenna measurement system.such as low cost, short development cycle, simple operation, modular and so on. It is easily to measure antenna of different frequency by use different frequency extension modules.The last, the radiation pattern of a W-band reflectarray antenna is measured by the antenna measurement system use of Fourth Harmonic Mixer. The measured results show the practicability and reliability of the antenna measurement system, the frequency multiplier and harmonic mixer developed in this paper can completely meet the requirements of laboratory millimeter wave antenna measurement.