US Government As Represented by the Secretary of the Army

Herbert Dropkin

Donald E Wortman

Richard P Leavitt

Dieter R Lohrmann

A random binary modulated sensor transmits a continuous wave r.f. signal ulated by a binary random bit pair code signal which is transmitted by an antenna. A return signal reflected from a target is received by the antenna. A receiver mixer modulates the return signal with the r.f. signal and a delay circuit delays the binary random bit pair code. A coorelator receives the modulated return signal and delayed binary random bit pair code for producing a doppler output signal. A separate r.f. path in which a portion of the modulated r.f. signal is variably attenuated and variably phase shifted is present to cancel noise signals generated by antenna mismatch in transmission.

Random binary modulated sensor

An orotron for generating near millimeter wavelength radiation at a selectable output frequency within a wide frequency range, in which the orotron output power is automatically tuned electronically at the selected output frequency. A piezoelectric electromechanical positioning device is connected between the two mirrors forming the open resonator of the orotron to determine the mirror separation in accordance with a position control signal. The electron beam acceleration voltage, which determines the orotron output frequency, and the position control signal are adjusted simultaneously so as to tune the output power at a single oscillation mode of the orotron resonator over a wide frequency range. In the preferred embodiment, the actual output frequency is detected and compared with the selected output frequency, and the beam acceleration voltage and mirror separation simultaneously adjusted to continuously tune and maintain the orotron output at the selected frequency.

Wideband electronic frequency tuning for orotrons

Method and apparatus for modulating coherent radiation generated by an orotron in accordance with a low voltage control signal applied to the diffraction grating to vary the grating-to-cathode voltage from the cathode-to-collector voltage over a selected voltage range determined by the maximum and minimum values of the control voltage. For amplitude modulation, the grating-to-cathode voltage is varied within a voltage range between a lower voltage at which the orotron output power starts to fall abruptly and a cutoff voltage at which coherent radiation ceases. For frequency modulation, the grating-to-cathode voltage is varied within a voltage range, including the point of maximum power output, where there is a minimum change of output power with a change in the grating-to-cathode voltage.

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Washington, DC, United States of America

Herbert Dropkin