Transmitting Circular-Polarized Phased Array with Self-Packaged, Direct Integrated Active Elements

A transmitting circular-polarized (CP) phased array based on self-packaging active direct integrated elements is presented in this communication. The input impedance of the magnetoelectric (ME) dipole with CP radiation is optimized to achieve consistent matching with the power amplifier (PA) transistor during beam scanning. De-coupling vias are added between adjacent ME dipoles to suppress mutual coupling, thereby overcoming the gain drop and axial ratio (AR) degradation at large beam-scanning angles. The air-filled suspended stripline (SSL) is used for input impedance matching and stabilization circuit of the PA transistor. The SSL structure not only realizes the self-packaging of the PA circuit, but also helps to improve heat dissipation. The active PA gain and power-added efficiency (PAE) under the large signal excitation during beam scanning are analyzed using electromagnetic-circuit co-simulation method. A 1 × 8-element CP PA integrated phased array (PAIPA) operating at 23 GHz is demonstrated. It supports a beam-scanning range of over ±50°. The experimental results show that the active element channels in the PAIPA have good ARs and radiation patterns. The channel active PA gain at 23 GHz with an input power of 22.5 dBm exceeds 8.8 dB, and the PAE is greater than 43%.