Novel Tunable Filter for Millimeter-Wave Spectrum Analyzer Over 100 GHz

Rapid progress in millimeter-wave wireless communication technologies requires accurate spectrum analysis in the frequency domain over 100 GHz. A tunable preselection filter is a key device in building such a spectrum analyzer. This paper proposes a new tunable filter as a preselector in the frequency range from 110 to 140 GHz. The filter was designed using a commercial electromagnetic simulator and two prototypes were evaluated. The first proved the tuning function in the working range but had a large insertion loss of . The second with various structural and manufacturing improvements achieved both tunability and insertion loss of <;10 dB.