Abstract: An LC filter structure and method for its fabrication, in which multiple shunt capacitors, multiple shunt inductors and multiple coupling inductors are printed on a metal layer formed on a thin dielectric substrate. The capacitors have first electrodes that are formed as spatially separated regions of the metal layer, and a common second electrode formed by a ground plane on the substrate. The shunt inductors are formed as spiral traces connected to the separated regions and to the ground plane, through conductive vias. The coupling inductors are similarly formed as spiral traces in the gaps between the separated regions, the ends of each coupling inductor being connected to respective adjacent regions of the metal layer.

Abstract: Apparatus and a corresponding method for predistorting an input signal applied to a radio frequency (RF) power amplifier, to compensate for amplifier distortion at high powers. The RF amplifier input and output signals are continuously monitored and difference signals are generated in an RF phase discriminator. The difference signals are converted to digital form and stored in a lookup table in the form of running averages of an RF amplifier gain compression value and an RF amplifier output phase value for each observed RF input power value. A predistorter module retrieves these values and predistorts the RF amplifier input by way of compensation.