Abstract: A top-via etch technique for forming dielectric membranes for thin film devices, the dielectric membrane being deposited on the upper planar surface of the substrate. After the thin film device is formed on the dielectric membrane, a photoresist etch mask is deposited on the entire upper planar surface of the substrate, including the thin film structure. Vias are formed through the dielectric membrane and the protective photoresist etch mask to expose the upper planar surface of the substrate along opposite first and second ends of the thin film device. The upper planar surface of the substrate is isotropically etched using a reactive ion etching technique for example, to form air gaps beneath the dielectric membrane. The etching process may be carried out in etch segments of predetermined intervals, each followed by a cool down period of a prescribed interval.

Abstract: An integrated RF avionics system having a common IF interface for diverse functions, such as radar, electronic waveform(EW) and communications/navigation/identification(CNI). The interface uses a segmented band of IF frequencies which are subdivided into two or more individual band segments separated by a guard band segment. The lower frequency band segment comprises a narrow band segment which is assigned to radar functions while the other or upper band segment comprises a wideband segment assigned to other functions such as EW and CNI functions. The guard band is not used for signal transmission, but is left unused to permit bandpass filters to reject signals in the adjacent unwanted segment, thus achieving frequency separation across the IF band while allowing the use of common hardware. The total IF range is sufficiently wide that radar, EW and CNI signals can be separated from each other with practical filters while being routed through a common IF switch network.

Abstract: A low VSWR, high isolation microwave matched coaxial transmission line power divider/combiner compensates for parasitic reactances with lumped compensating elements to yield a compact, densely packable structure.