Design and Simulation of a Low Loss Ka-band SPDT Switch for Time Modulated Array Beam Steering

In Time modulated arrays (TMAs), a switch is used instead of a phase shifter, which reduces the area, complexity, power consumption and the overal cost of the array. The TMA uses the switch as a control element for array weighting for the purpose of beam forming and beam steering. To lower the IC cost, the IC is designed to be as compact as small as possible. Moreover, the inexpensive CMOS 180 nm technology of TSMC is used for IC fabrication. The designed SPDT switch has 1.85 dB loss at 33 GHz, more than 17 dB isolation in Ka-band, and its area is 0.086 mm2. Compared to other switches designed in CMOS180 nm, this work has the lowest loss and area (up to now), and covers Ka-band completely. Another critical element of an array is a power combiner/divider with minimum area. Because this array has 4 elements, it needs a 4-way power divider. Four switches and power divider form a TMA IC, which covers 26.5 to 37.6 GHz with an area of 0.7 by 1.48 mm2. The power consumption of the array is zero since all the elements are passive and do not consume any power.