Design of W-band PIN Diode SPDT Switch with Low Loss

Abstract

A W-band PIN diode single pole double throw (SPDT) switch with low insertion loss (IL) was successfully developed using a hybrid integration circuit (HIC) of microstrip and coplanar waveguide (CPW) in this paper. In order to achieve low loss of the SPDT switch, the beam-lead PIN diode 3D simulation model was accurately established in Ansys High Frequency Structure Simulator (HFSS) and the W-band H-plane waveguide-microstrip transition was realized based on the principle of the magnetic field coupling. The key of the proposed method is to design the H-plane waveguide-microstrip transition, it not only realizes the low IL of the SPDT switch, but also the direct current (DC) bias of the PIN diode can be better grounded. In order to validate the proposed design method, a W-band PIN diode SPDT switch is fabricated and measured. The measurement results show that the IL of the SPDT switch is less than 2 dB in the frequency range of 85 to 95 GHz, while the isolation of the SPDT switch is greater than 15 dB in the frequency range of 89.5 to 94 GHz. In the frequency range of 92 to 93 GHz, the IL of the SPDT switch is less than 1.65 dB, and its isolation is higher than 22 dB. Switch rise time and switch fall time of the SPDT switch are smaller than 29ns and 19ns, respectively. Good agreement between the simulations and measurements validates the design method.

Radar cross-section reduction using digital programmable metamaterials

“…Figure 5 shows the design of a MTM supercell that consists of nine programmable unit cells, arranged in the form of an organized matrix along the XY-plan, which can be controlled by an external control system such as a Field Programmable Gate Array (FPGA) using SPDT PIN diodes [14] that works at w-band. When all the switches are opened (OFF-state), the supercell consists of a disconnected type unit cell and behaves as a magnetic conductor at a frequency of 95.3 GHz, which has a zero-phase re ection and an absorption rate of 96%.…”