In this paper, a symmetrical fixed-frequency scanning leaky-wave antenna with dual polarizations (DP) based on the gap waveguide (GW) is proposed. The antenna operates in 5G millimeter wave band and is comprised of two side-by-side GWs and 96 DP radiating elements. The antenna is simulated and measured, achieving the scanning range of exceeding 95° and a peak gain of 14.5 dBi at 26.5 GHz.
A dual-band reconfigurable frequency selective surface (RFSS) is designed using characteristic mode (CM) analysis. By observing the modal behaviors of the two basic structures (microstrip line and square ring), an appropriate combination of them forms the initial element with a bandpass feature. In addition, the PIN diode is placed in the middle of the microstrip line so that the element’s resonant frequency varies with its ON/OFF state. Full-wave simulation shows the design of dual-band RFSS operating at 8.8 GHz and 10.4 GHz, which validates the proposed CM design.
A compact antenna feeding calibration network is proposed in this paper, aiming to provide a versatile and reliable feeding calibration integrated network for X-band phased arrays. Based on gap coupling theory and series-fed structure, the proposed calibration network is realized by the multi-layer couplers and a serpentine feedline. Meanwhile, the isolated metal columns and metal shielding boxes are designed to effectively improve the mutual coupling. Experimental data indicate that the fluctuations of coupling amplitude and phase are below 4.7 dB and 1.5°, the voltage standing wave ratio (VSWR) of each network port is below 1.25 and the isolation at the antenna end is greater than 53 dB.
Compared with PIN diode, varactor diode has more flexible phase manipulation capabilities [1] , [2] . By integrating varactor diode on the reflective meta-atom and changing the reverse bias voltage of varactor diode, the reflective phase can be continuously adjusted from 0 to 2π to achieve reconfigurable functions [3] .
This paper proposed the design and implementation of a Ka-band eight-channel transmit beamformer for SATCOM phased array, which employs the 0.13-µm SiGe Bi-CMOS technology and the wafer-level chip-scale packaging (WLCSP) technology. By using the switched-type attenuator and the active vector modulated phase shifter, the beamformer only consumes a quiescent current of 180 mA under 1.6-V supply voltage. The measurements show that from 27 to 31 GHz, a single-channel gain of 19.4~22.7 dB and a minimal OP1dB of 9.3 dBm can be achieved. Meanwhile, the measured RMS gain error is less than 0.48 dB and the measured RMS phase error is below 2.6°. The total size of the chip is 5.2×5.6 mm2 including pads.
