Patent ID: 9571132
Date: 2017-02-14
CPC Classifications: H01Q,H04B,H04L

Claim:
1. A radio transmitter system comprising a transmitter adapted to be responsive to an input for deriving a carrier frequency output wave modulated by the input; an antenna system that is electrically short at the carrier frequency; an impedance matching network for coupling the transmitter output wave to the antenna system and for matching the output impedance of the transmitter to the antenna system impedance; the impedance matching network including: (a) a primary circuit coupled to be responsive to the transmitter output wave, (b) a secondary circuit including the antenna system, the primary and secondary circuits respectively including first and second sets of impedance components, and (c) magnetic or capacitive coupling of the primary circuit to the secondary circuit, the magnetic coupling being an air core transformer arrangement having first and second transformer windings respectively included in the primary and secondary circuits, the capacitive coupling including a capacitive arrangement having a first electrode connected to be responsive to a voltage of the primary circuit and a second electrode connected to supply a voltage to the secondary circuit; the coupling and impedance components of the primary and secondary circuits being arranged for causing the matching network to have a voltage versus frequency response including at least two horns approximately symmetrically located on opposite sides of the carrier frequency, the spacing of the horns from each other being such that the matching network has a pass band approximately equal to the bandwidth of the modulation.