Abstract: A filter of the present invention creates a cavity filter that can be embedded within the inner layers of a printed circuit board. The embodiment can provide for a tunable microwave filter with lower loss, lower manufacturing cost and higher production yields. In addition, the tunable microwave includes a temperature compensation means to accommodate an electrical characteristic of filter with regard to the temperature variation. Such temperature compensation embodiment can be embedded into the upper layer communicably associated with the processor. For performing intelligent temperature compensation, the processor can include a look-up table of tuning values for controlling can store a set of temperature offset value that can modify the tuning table.

Abstract: A suspended line resonator and a tunable filter comprising multiple suspended line resonators. A microstrip resonator and a tunable filter comprising multiple microstrip resonators. A suspended substrate resonator and a tunable filter comprising multiple suspended substrate resonators.

Abstract: A resonator having piezoelectric properties is tuned to respond at a specific overtone of its parallel plate resonant frequency. A channel is etched in a blank to confine the oscillations to a predefined area thereby maximizing a predetermined overtone. The position and dimension of the channel are selected to confine the oscillation to a radius that maximizes the response at a desired frequency. The desired frequency is a predetermined overtone of the fundamental frequency. The channel limits the area of oscillation of the blank. The channel may be formed using grooves or slots. The slots are arranged to form a ring. The channel may be positioned inside or outside an electrode.