An LTCC Phase Shifter with an SPDT Switch for a 5.8GHz-Band Active Integrated Phased Array Antenna

5.8 GHz band digital phase shifters to control a beam direction for an active integrated phased array antenna are designed. The 4-bit phase shifters with integrated GaAs FET SPDT switches are integrated with an LTCC substrate. We realized a low loss 4-bit LTCC phase shifter with the size of 10 mm times 13 mm times 0.55 mm. From the simulation results, the insertion loss of LTCC phase shifter without the switch is simulated with about 0.5 dB/bit. The insertion loss of the LTCC phase shifter integrated with the GaAs FET SPDT switches and phase error are measured to be about 2.3 dB/bit and less than 15deg, respectively.