An MEMS Phase Shifter With High Power Handling for Electronic Beam Tilt in Base Station Antennas

This letter presents the implementation of RF MEMS-based phase shifter with high power handling capabilities (measured IP3 >63 dBm), high phase, and amplitude linearity (measured rms deviation <;±1.56° and ±0.16 dB) for cellular applications. Two phase shifter circuits are designed and tested with steps of ±3° and ±17.5° at 900 MHz to efficiently perform an electronic beam tilt for an eight-element array with more than 0.9° accuracy and up to 10° tilt can be obtained. The measured insertion and return loss for the largest phase state are 1.3 and 13 dB, respectively. For experimental validation, a 3 × 2 array of angled dipole patch antennas is designed and fabricated and four different scans are successfully measured showing a maximum deviation of ±0.6° only for the scan angle.