Planar Signal Coupler for Cryogenic Arrays

The patent replaces free-space optical/mechanical coupler systems with an integrated planar circuit implementation. The signal coupler is constructed using printed circuit board techniques with conductive traces on dielectric substrates, eliminating the need for bulky free-space components like wire grid splitters or thin dielectric film splitters. This substitution of mechanical/free-space systems with planar circuit technology achieves the same signal coupling function while dramatically reducing device footprint.

The invention transitions from three-dimensional free-space coupling components to a two-dimensional planar circuit layout. By implementing the signal coupler as a flat, integrated circuit on a PCB substrate, the design exploits the planar dimension to achieve compactness while maintaining coupling functionality through carefully designed trace geometries and impedance matching structures.

The patent replaces free-space optical couplers with integrated planar circuit implementations that can be directly mounted on cryogenic substrates. This elimination of intermediate free-space components reduces the thermal path length and minimizes the volume requiring cryogenic cooling, thereby reducing the overall cooling requirements while maintaining signal coupling functionality at cryogenic temperatures.

The invention merges the signal coupling function directly into the planar circuit substrate, eliminating separate free-space coupler components. By integrating the coupler functionality into the same planar platform as other circuit elements, the design reduces the total volume requiring cryogenic cooling and simplifies the thermal management architecture.

The patent implements local quality variations within the planar circuit design to compensate for cumulative signal loss across the array. Each coupler element in the array is designed with locally optimized trace geometries, impedance values, or coupling coefficients that are specifically tailored to provide the required power distribution. This allows identical-looking couplers to be manufactured with precise local parameter adjustments that ensure consistent output power levels across all array elements.

The invention employs parameter changes in the planar circuit design, such as varying trace widths, dielectric thicknesses, or coupling gap dimensions at different locations within the array. These parameter adjustments are made while maintaining overall manufacturing uniformity, allowing each coupler element to be fabricated using the same process but with locally optimized parameters that compensate for signal attenuation and ensure consistent power distribution across all outputs.

The patent implements a universal planar circuit architecture where a single signal input can serve multiple coupler elements in the array. The design uses a shared signal distribution network with carefully designed impedance matching and power splitting structures that allow one input to provide consistent power levels to multiple outputs. This multi-functional approach eliminates the need for separate inputs for each coupler while maintaining power consistency through integrated circuit design.

The invention segments the signal distribution function across the planar circuit, creating dedicated signal paths and power splitting networks that distribute the input signal to multiple coupler elements. By segmenting the distribution network into controlled impedance traces and power splitting junctions, the design achieves consistent power levels at each coupler output while using a single input, thereby reducing electrical and space requirements compared to providing separate inputs for each coupler.