Dynamic range of a P-I-n-diodes based SP4T switch-IC for broadband Ka-band satellite communication applications

This paper focuses on the investigation of the dynamic range of a single-pole quadrouple-throw P-I-N-diode integrated switch circuit which is the basic building block of a 4 × 4 re-configurable microwave switch matrix for Ka-band satellite downlink (17 - 22 GHz). The noise figure and the level of third order intermodulation products, in this case passive intermodulation, which can interfere with in-band signals depends on the direct control current (DC) of the P-I-N-diode junction. We found, that at 10 mA control current per path, an optimal compromise for dynamic range, noise figure and (DC-) energy efficiency is achieved. At that point, the noise figure evaluates to 1.32 (1.2 dB) and the input third order point of intercept (I-TOI) amounts to 42.5 dBm. The distortion free dynamic range DR results to 74.0 dB at an equivalent noise bandwidth of 25 GHz of the switch IC. In disregard of significantly increased third order products existent at power levels of about - 30 dBc, a maximum dynamic range DR_max of ≈ 98.8 dB is available.