# US 5,351,054 A · Radar target with delayed reply means

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 5,351,054 A
- Document ID: US5351054A
- Status: Granted
- Kind: A
- Application number: 07/951,156
- Filed: 1992-09-25
- Granted: 1994-09-27
- Earliest claimed: 1991-10-07
- Assignees: Duane G. Fredericks
- Inventors: Duane G. Fredericks; Herbert W. Rosebrock
- Web page: https://patentgrep.com/patent/US5351054A

## CPC

- G01S 7/4052: {by simulation of echoes}
- G01S 13/767: {Responders; Transponders (teaching or practice apparatus for gun-aiming or gun-laying using reflecting targets or active targets F41G3/26)}
- G01S 13/78: discriminating between different kinds of targets, e.g. IFF-radar, i.e. identification of friend or foe (G01S13/75, G01S13/79 take precedence)
- G01S 13/913: {for landing purposes}
- H01Q 3/2682: {Time delay steered arrays}
- G01S 7/4095: {the external reference signals being modulated, e.g. rotating a dihedral reflector or modulating a transponder for simulation of a Doppler echo}
- G01S: RADIO DIRECTION-FINDING; RADIO NAVIGATION; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION OR RERADIATION OF RADIO WAVES; ANALOGOUS ARRANGEMENTS USING OTHER WAVES
- H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72)

## Abstract

An apparatus for producing an electromagnetic signal which simulates the radar signature of a vertical takeoff and landing vehicle is disclosed. The apparatus contains a means for receiving a radar signal, modulation means for modifying the radar signal, means for dividing the modulated signal into at least a first divided signal and a second divided signal, means for producing a Doppler composite signal, means for mixing the composite Doppler signal with the first divided signal, means for attenuating the second divided signal, and means for combining the attenuated second divided signal and the composite Doppler signal.

## Claims

### Claim 1

An apparatus for producing an electromagnetic signal, wherein said apparatus is comprised of:
(a) means for receiving a radar signal which has a frequency of from about 1 to about 94 gigacycles;
(b) modulation means for modifying said radar signal, thereby producing a modulated signal;
(c) means for dividing said modulated signal into at least a first divided signal and a second divided signal;
(d) means for producing a Doppler composite signal produced by combining a third signal, and a fourth signal;
(e) means for reducing the velocity of propagation of said radar signal thereby producing a delayed radar signal;
(f) means for modulating said composite Doppler signal with said delayed radar signal, thereby producing a modulated delayed radar signal;
(g) means for attenuating said modulated delayed radar signal, thereby producing an attenuated modulated delayed radar signal; and
(h) means for combining said delayed radar signal and said composite Doppler signal, thereby producing a combined signal; and
(i) means for transmitting said combined signal to a radar source.

### Claim 2 (depends on 1)

The apparatus as recited in claim 1, wherein said first modulation means is an inbound/outbound Doppler modulator.

### Claim 3 (depends on 1)

The apparatus as recited in claim 1, wherein said said means for mixing said composite Doppler signal with said first divided signal is a double sideband modulator.

### Claim 4 (depends on 1)

The apparatus as recited in claim 1, wherein said apparatus is further comprised of at least five voltage controlled oscillators.

### Claim 5 (depends on 1)

The apparatus as recited in claim 1, wherein said apparatus is further comprised of a triangular function generator.

### Claim 6 (depends on 1)

The apparatus as recited in claim 1, wherein said apparatus is further comprised of a modified cosine generator.

### Claim 7 (depends on 3)

The apparatus as recited in claim 3, wherein said first modulation means is an inbound/outbound Doppler modulator.

### Claim 8 (depends on 7)

The apparatus as recited in claim 7, wherein said said means for mixing said composite Doppler signal with said first divided signal is a double sideband modulator.

### Claim 9 (depends on 8)

The apparatus as recited in claim 8, wherein said apparatus is further comprised of at least five voltage controlled oscillators.

### Claim 10 (depends on 9)

The apparatus as recited in claim 9, wherein said apparatus is further comprised of a triangular function generator.

### Claim 11 (depends on 10)

The apparatus as recited in claim 10, wherein said apparatus is further comprised of a modified cosine generator.