Wideband Multi-channel RF Selection Unit

Design and implementation of a wideband multichannel RF selection unit has been discussed in this article. It consists of two input channels, one Built-in test (BIT) source and four output channels. Any input channel/BIT can be routed to any output channel. It comprises of three sections: 1)RF section; 2)Power Supply, Control & BIT section; 3)AC-DC conversion section. It is realized as stack up of two PCBs on either side of mechanical housing. Top side of housing comprises of VHF to C band RF section. Bottom side comprises of VHF band RF section, VHF to C band BIT section, Power supply, digital controls circuitry and AC-DC converter. PCB s are hybrid multilayer. Vertical coax based RF transitions are used for routing BIT and RF signals to RF output paths, resulting in compact integration. Digital controls and power supply are connected from bottom PCB to top PCB via board to board connector. Realized unit measures 10.7 dB min Gain with < ±2 dB Gain Flatness and ≤5.3 dB Noise figure over frequency and temperature. It provides very high isolation (>90 dB) among output channels and very low output spurious. The unit works on 230 VAC supply. Realized unit has cleared Environmental stress screening (ESS) testing successfully.