ACCURATE PASSIVE RANGING TECHIQUES

Monopole and dipole antennas have been determined to radiate most efficiently when the size of the antenna is proportional to the frequency being transitted or received, ie.e, one-quarter, one-half or one wavelength. As the operating frequency is varied from that ideal frequency, nulls begin to develolp which threaten the integrity of the communication link. Experience has shown that small excusions (+/- 50% of the resonent frequency) can be achieved without degrading performance by use of matching devices. But, larger bandwidths are normally accomodated by active high impedence tuning devices and couplers. This investigation will evaluate new low impedance passive broadbanding techniques to produce low profile, high performance antennas. Several Astron innovative techniques are proposed which will significantly decrease size without effecting gain and efficiency.