Research of millimeter wave gain equalizer using microstrip SIR and waveguide resonator respectively

Millimeter wave gain equalizers were designed using microstrip shorted SIR (Stepped Impedance Resonator) and waveguide resonator respectively. Traditionally, millimeter wave gain equalizer is composed of waveguide with electromagnetic wave absorber in resonator. However, putting the wave absorber into resonator directly is very hard to control the reflection coefficient and the max attenuation point for we cannot precisely control the position and amount of electromagnetic wave absorber in the waveguide resonator when we are assembling the gain equalizer. In this paper, the millimeter wave gain equalizer is fulfilled by microstrip stepped impedance resonator with thin film resistance integrated and a new waveguide resonator structure. The former is suitable for small power situation and easy to integration, the latter is adaptive for big power condition. The simulation results show the proposed equalizers operated from 31 to 37GHz and 26.8 to 40 GHz. For the microstrip structure, S11 and S22 are less than -13dB and the value of equalization are about 12dB. For the waveguide structure, S11 and S22 are less than -15dB and the value of equalization are about 11dB.