Abstract: A low-pass filter comprises input and output transmission lines, a high impedance, series transmission line coupling the input and output transmission lines, a first meandered transmission line having one or more pairs of coupled transmission lines and one or more transition transmission lines connecting respective pairs of coupled transmission lines together, wherein one of the coupled transmission lines is connected to the input transmission line, and a second meandered transmission line having one or more pairs of coupled transmission lines and one or more transition transmission lines connecting respective pairs of coupled transmission lines together, wherein one of the coupled transmission lines is connected to the output transmission line. A high-pass filter is similar to the low-pass filter, except it has a pair of series coupled transmission lines in place of the series transmission line. The transmission lines are formed on a dielectric subtrate.

Abstract: A design methodology for a DRO that facilitates the development of the DRO. The methodology involves providing an electrical length of approximately 180 degrees or a multiple thereof from a region interior to a field effect transistor to a puck-resonator line interaction region, providing an electrical length of approximately 180 degrees or a multiple thereof from a region interior to the field effect transistor to the signal end of a source feedback transmission line, and providing an electrical length of approximately 90 degrees or an odd multiple thereof from a varactor diode signal ground to a puck-tuning line interaction region. Other aspects relate to a DRO resonator transmission line and a DRO tuning transmission line having a portion formed on a higher dielectric substrate to concentrate the electromagnetic field, and a portion on a lower dielectric substrate to expand the electromagnetic field near the dielectric resonator puck.

Abstract: A directional coupler characterized as having improved directivity. The directional coupler and methodology uses enhanced destructive interference to reduce the leakage at the output port of a signal incident at the coupled port of the coupler thereby giving the coupler improved directivity. The directional coupler creates this enhanced destructive interference by the introduction of impedance discontinuities in the coupled transmission lines. The impedance discontinuity in the coupled transmission lines can take on many forms, such as recesses at the coupling sides of the coupled transmission lines, protrusions at the non-coupling sides of the coupled transmission lines, or both. Another directional coupler is capable of being tuned for different coupling levels. This coupler comprises adjacent conductors between the coupled transmission lines that are connected, as required, to the coupled lines to change the coupling level.