Millimeter-Wave Planar Antenna Array Based on Modified Bulk Silicon Micromachining Technology

In this communication, a planar antenna array is proposed in millimeter-wave bands by using a modified bulk silicon micromachining technology. The proposed antenna array is designed and fabricated based on air-filled microstrip line structures. By periodically blocking the microstrip line, fringing electric fields along the microstrip lines are excited in phase, which contributes to achieving high gain performance with a relatively compact feeding structure. Moreover, the proposed antenna array is designed and fabricated by a modified bulk silicon micromachining technology. The process is quite suitable for designing low loss antennas in millimeter-wave bands. In the process, the silicon wafers are deeply etched and gold-plated. As a result, microstrip line structures in the proposed antenna array are filled with air medium, which mitigates dielectric loss and improves radiation efficiency. A prototype of the proposed antenna array is fabricated and tested to verify the design strategy. The dimension of the antenna array is 49.40 × 20.00 × 0.75 mm
³
. The simulated -10 dB bandwidth is 58.8-59.7 GHz and the measured bandwidth is 58.8-59.5 GHz. In the operating band, the maximum simulated gain of the proposed antenna is 19.8 dBi and the minimum simulated gain is 18.3 dBi. The measurement results illustrate that the maximum gain of the proposed antenna array is 18.8 dBi and the minimum gain is 17.0 dBi.