Development of 60 GHz Phased Antenna Arrays Using Liquid Crystal Phase-shifters

Liquid crystal based antenna arrays with beam steering capability in one dimension for 60 GHz band is presented. Two array designs are discussed. First design uses slotted patch antenna as an array element. For this array a compact, planar, liquid crystal based meander line phase shifter is designed which have a maximum differential phase shift of 47°. The array comprises of a 4×1 slotted patch array, which is able to scan up to 14° in the E-plane. Second design uses patch antenna as an array element. In this array the phase shifters are liquid crystal based meander lines, each providing a maximum differential phase shift of 38°. The array elements (the patch antennas) are coupled to the microstrip feed line through coupling gaps. These gaps are adjusted in order to uniformly excite the antenna patches. The designed array comprises of a 4 × 1 patch array, which is able to scan up to 9° in the E-plane as the bias on the liquid crystal changes from zero to saturation voltage.