Time domain radio transmission system

Abstract

A time domain communications system wherein a broadband of time-spaced signals, essentially monocycle-like signals, are derived from applying stepped-in-amplitude signals to a broadband antenna, in this case, a reverse bicone antenna. When received, the thus transmitted signals are multiplied by a D.C. replica of each transmitted signal, and thereafter, they are, successively, short time and long time integrated to achieve detection.

Description

[0001]This application is a continuation of application Ser. No. 07 / 368,831, filed on Jun. 20, 1989; which is a continuation-in-part of application Ser. No. 07 / 192,475, filed on May 10, 1988; which is a continuation-in-part of application Ser. No. 06 / 870,177, filed on Jun. 3, 1986, now U.S. Pat. No. 4,743,906; which is a continuation-in-part of application Ser. No. 06 / 677,597, filed on Dec. 3, 1984, now U.S. Pat. No. 4,641,317.[0002]This application is also a continuation-in-part of International Application No. PCT / US90 / 01174, filed on Mar. 2, 1990, which is a continuation-in-part of International Application No. PCT / US89 / 01020, filed on Mar. 10, 1989. Said PCT Application No. PCT / US89 / 01020 is also a continuation-in-part of U.S. application Ser. No. 07 / 010,440, filed on Feb. 3, 1987, now U.S. Pat. No. 4,813,057.FIELD OF THE INVENTION[0003]This invention relates generally to signal transmission systems, and particularly to a time domain system wherein spaced narrow signal bursts, i...

AI Technical Summary

Benefits of technology

[0011]As a second aspect of the invention, a radio transmitter is a pulse creating switching which is closely and directly connected to antenna element, thus eliminating transmission line effects which tend to undesirably lengthen the transmitted signal.

[0015]As still a further feature of this invention, transmitted burst signals are varied in time pattern (in addition to a modulation pattern for communications or telemetry). This greatly increases the security of the system and differentiates signals from nearly, if not all, ambient signals, that is, ambient signals which are not synchronous with transmitted burst signals, an effect readily achievable. This also enables the employment of faster repetition rates with radar which would, absent such varying or dithering, create range ambiguities as between returns from successive transmission and therefore ranges. Burst signals are signals generated when a stepped voltage change is applied to a broadband antenna, such as a reverse bicone, but flat, antenna.

[0017]As still a further feature of this invention, the repetition rate of burst signals would be quite large, say, for example, up to 100 MHz, or higher, this enabling a very wide frequency dispersion, and thus for a given overall power level, the energy at any one frequency would be extremely small, thus effectively eliminating the problem of interference with existing radio frequency based services.

[0022]Finally, and of very substantial significance, is that the light modulator referred to the preceding paragraph provides what is believed to be a breakthrough in conveniently enabling frequency modulation of light signals passing, for example, through a fiber optic having a variable refractive index with bias voltage. Additionally, it may be employed as a selectable delay device.

Problems solved by technology

As a further consideration, practical power restraints in the past have been generally limited to the application of a few hundred volts of applied signal energy to the transmitting antenna.

In this manner, no metallic triggering communications line extends to the antenna which might otherwise pick up radiation and re-radiate it, adversely effecting signal coupling to the antenna and interfering with the signal radiated from it, both of which tend to prolong the length of a signal burst, a clearly adverse effect.

Images