Abstract: An integrated filter circuit and a method of fabrication are disclosed, wherein the integrated filter has an input and an output parasitic shunt impedance. Input and output electrical components are coupled to the input and output terminals, respectively, to reduce the input and output parasitic shunt impedances. The input and output electrical components each include one of a coil, a section of transmission line, a coil and tuneable capacitance connected in a series tuned circuit, or a coil and tuneable capacitance connected in a parallel tuned circuit.

Abstract: An interleaved antenna array is disclosed in conjunction with an improved multiple transmitter antenna system for simultaneously generating two independent groups of composite radiation patterns for two separate pluralities of independent radio devices. A first plurality of isolated independent radio transmitters is coupled, without any signal cancellation, to each and every one of a first plurality of independent antenna elements which form a first group of composite radiation patterns for these transmitters. A second plurality of transmitters is likewise coupled to a second plurality of antenna elements which create a second group of composite patterns for these transmitters. The antenna elements of the first and second pluralities are alternately circumferentially disposed about a central axis and each produces a 90.degree. half power beam width radiation pattern which is directed radially away from the central axis. First and second combining networks produce 90.degree.

Abstract: An improved gain antenna which is vertically mounted to a horizontal ground plane is disclosed. The gain antenna substantially consists of a radiating conductor having first and second ends and a centrally located feed point, and phasing apparatus electrically connected to the conductor for producing a predetermined current distribution. The phasing apparatus produce shortened out of phase current sections along the length of the conductor. Centrally feeding the gain antenna results in an improvement in the bandwidth and input impedance. The conductor consists of a linear section of coaxial cable which extends vertically from the horizontal ground plane to approximately the central feed point and a solid conductor rod which extends vertically upwardly from the central feed point. Current phasing apparatus having improved bandwidth and reactance characteristics are also described.