Antenna for radar system - has transmitter receiver elements coupled to tuned stage

摘要

An antenna system of the type used in small radar systems has a pair of quarter wavelength lines (1, 2) coupled to a ballast resistor (3) with connecting points (4, 5) coupled to a transmitter oscillator (6) and receiver diode (7) respectively. The antenna is coupled to the connecting point (8). The antenna section (91) has a base point impedance that is frequency dependent and may be tuned. This is constructed as a series resonance circuit with a series resistance in the range 30-60 ohms; a parallel resistance of 60-90 ohms and an emitting resistance of 55 ohms. ADVANTAGE - Optional directional characteristic.