Compact wideband passive and active component chips for radio astronomy instrumentation

Paper in proceeding, 2019

In the 2SB receivers, the rejection ratio is determined among other factors by the performance of the quadrature hybrids. We have developed and fine‐tuned components that intended to be used in the IF chain and meet the requirements for new generation of compact wideband 2SB receivers. We present here the design and characterization of three multi‐section compact wideband 3 dB quadrature couplers (coupled line coupler – Lange coupler–coupled line coupler). Specifically, the miniaturized 3‐section hybrid chip made using thin‐film technology utilizes gold plated transmission lines and air bridges to connect the fingers of the Lange coupler (middle section The hybrids were designed to have the amplitude and phase imbalance better than 0.6 dB and ±3° respectively over a 3.5-12.5 GHz and 4-16 GHz frequency bands. Experimental verification of the assembly at 293 K and 4 K shows very good agreement between the measurements and simulations. Additionally, we demonstrate the suitability of the miniature hybrid chips, by implementing them in a balanced amplifier designed using a modular approach, which demonstrated promising results.