Retrodirective transmit and receive radio frequency system based on pseudorandom modulated waveforms
First Claim
1. A transmit and receive electromagnetic apparatus, comprises:
- a transmit antenna array having at least one transmit element with each transmit element configured to transmit electromagnetic radiation into space, anda receive antenna array having a plurality of receive elements with specific locations relative to the at least one transmit element; and
RF electronic components that drive each transmit element with a pseudorandom modulated (PRM) waveform that is generated at baseband frequencies by a digital phase shift keying (DPSK) function, translated to an intermediate frequency (IF) digitally, and imposed on an RF carrier by single-sideband frequency up-conversion using a solid-state local oscillator.
1 Assignment
0 Petitions
Accused Products
Abstract
Embodiments provide radio-frequency systems that can automatically detect, focus-on, and track objects in the environment without the need for expensive electronic scanning and phase-shifting components. Some embodiments are directed to retrodirective systems including: (1) quiescently broadcast pseudorandom-modulated radiation, such as pseudorandom bit sequences, in the absence of a target, over a field-of-view comparable to the beam solid angle of a single element in the transmit array; (2) a receive antenna element or array, in a desired spatial relationship with respect to the transmit antenna array, that receives reflected pseudorandom radiation from a target; and (3) an electronic signal-processing and feedback channel between the receive and transmit arrays that carries out cross-correlation between the received radiation and the transmitted pseudorandom signals and computes complex correlation coefficients to form a re-transmitted beam. Some embodiments are useful for short-range applications involving small and fast moving targets.
-
Citations
12 Claims
-
1. A transmit and receive electromagnetic apparatus, comprises:
-
a transmit antenna array having at least one transmit element with each transmit element configured to transmit electromagnetic radiation into space, and a receive antenna array having a plurality of receive elements with specific locations relative to the at least one transmit element; and RF electronic components that drive each transmit element with a pseudorandom modulated (PRM) waveform that is generated at baseband frequencies by a digital phase shift keying (DPSK) function, translated to an intermediate frequency (IF) digitally, and imposed on an RF carrier by single-sideband frequency up-conversion using a solid-state local oscillator. - View Dependent Claims (2)
-
-
3. A transmit and receive electromagnetic apparatus, comprising:
transmit and receive antenna arrays with the transmit array having at least one transmit elements, each transmit element transmitting electromagnetic energy in a unique and quasi-orthogonal PRM waveform in the absence of a target, and wherein each transmit element has a corresponding receive element in the receive antenna array, each receive element collecting a portion of the electromagnetic energy reflected from any target, and wherein a spatial configuration exists between the transmit and receive antenna arrays whereby phase-preserving correlative signal processing between corresponding receive and transmit elements, using electronic components connecting corresponding receive and transmit elements, generates a re-transmission of electromagnetic energy from the transmit array that is retrodirective with respect to the electromagnetic energy reflected from the target to the receive array, and whereby the transmitted electromagnetic energy is steered automatically toward the target. - View Dependent Claims (4, 5, 6, 7, 8, 9, 10, 11, 12)
Specification