Design and Development of High Frequency Passive and Active Micromachined Antennas

This paper presents methodology for the design and development of passive and active micromachined antennas operating in the microwave and millimeter wave frequency region. The passive antenna design is based on dividing the circuit into bulk feed line, micromachined line to bulk feed line transition and membrane supported micromachined antenna. Each region is modeled using full wave electromagnetic simulation software HFSS. In the active antenna, the two-port membrane supported micromachined antenna is connected in positive feedback path of an MMIC amplifier chip using bulk feed lines. The fabricated micromachined passive antenna element resonated at 34.2 GHz. This antenna exhibited a bandwidth of 1.4 GHz for VSWR<2.0. The measured 3-dB E-plane and H-plane beam widths are 65-70 degrees that agrees fairly well with the simulated results. The initial active antenna oscillated at 35.64 GHz with 47.2 dBm power and showed a clean spectrum.