High power signal communications within a power limit

Patent metadata

Field	Value
Publication number	US-10630322-B2
Application number	US-201815974446-A
Country	US
Kind code	B2
Filing date	May 8, 2018
Priority date	May 8, 2018
Publication date	Apr 21, 2020
Grant date	Apr 21, 2020

Abstract

An RF communication system includes a wideband receiver for receiving an RF signal; a wideband receive signal path for processing the received RF signal, a wideband transmit signal path for processing a transmit RF signal to be transmitted; a wideband transmitter for transmitting the transmit RF signal at a selected transmit frequency and a selected transmit polarization; and a processor for controlling a plurality of beam forming circuits for performing signal processing and waveform generation, wherein the processor maximizes an effective radiated power (ERP) of the communication system within a predetermined ERP limit by switching the wideband transmitter between at least one of multiple transmit frequencies and multiple transmit polarizations to form an aggregate, time-averaged signal as the transmit RF signal.

First claim

The invention claimed is:

1. A radio frequency (RF) communication system comprising:
a wideband receiver for receiving an RF signal;
a wideband receive signal path for processing the received RF signal,
a wideband transmit signal path for processing a transmit RF signal to be transmitted;
a wideband transmitter for transmitting the transmit RF signal at a selected transmit frequency and a selected transmit polarization; and
a processor for controlling a plurality of beam forming circuits for performing signal processing and waveform generation, wherein the processor maximizes an effective radiated power (ERP) of the communication system within a predetermined ERP limit by switching the wideband transmitter between at least one of multiple transmit frequencies and multiple transmit polarizations to form an aggregate, time-averaged signal as the transmit RF signal, wherein the processor further
determines a time to switch the selected transmit frequency, as a function of a transmission power of the communication system and the predetermined ERP limit,
determines whether the communication system is using different polarization schemes, when it is the time to switch the selected transmit frequency;
switches the wideband transmitter to a new transmit frequency separated from the selected transmit frequency by a predetermined bandwidth, when it is determined that the communication system is not using different polarization schemes;
determines a time to switch the selected transmit polarization, as a function of a transmission power of the communication system and the predetermined ERP limit, when it is determined that the communication system is using different polarization schemes;
switches the wideband transmitter to the new transmit frequency, when it is not the time to switch the selected transmit polarization; and
switches the wideband transmitter to a new transmit polarization, when it is the time to switch the selected transmit polarization, to transmit the aggregate, time averaged low power signal at rotating polarizations and frequencies, by the wideband transmitter.

2. The RF communication system of claim 1 , wherein the wideband receive signal path includes a wideband bandpass filter to separate two or more carriers or signals in the received RF signal, a wideband amplifier to amplify an output signal from the bandpass filter and an Analog-to-Digital Converter (ADC) to convert an output signal from the wideband amplifier to a digital signal for processing by the processor.

3. The RF communication system of claim 2 , wherein the wideband ADC is a monobit ADC.

4. The RF communication system of claim 2 , wherein the wideband receive signal path includes an Automatic Gain Controller (AGC) to control an input power into the wideband ADC.

5. The RF communication system of claim 1 , wherein the wideband transmit signal path includes a wideband Digital-to-Analog Convertor (DAC) to convert a digital output from a respective beam forming circuit controlled by the processor to an analog signal, a bandpass filter to separate two or more carriers or signals from the analog signal, and a power amplifier to amplify the separated two or more carriers or signals for transmission.

6. The RF communication system of claim 5 , wherein the wideband DAC is a monobit DAC.

7. The RF communication system of claim 5 , wherein the wideband transmit signal path includes an Automatic Gain Controller (AGC) to control an input power into the power amplifier.

8. The RF communication system of claim 1 , wherein the predetermined ERP limit is an EPR limit set by the Federal Communications Commission (FCC).

9. A radio frequency (RF) communication method, the method comprising:
receiving an RF signal by a wideband receiver;
processing the received RF signal by a wideband receive signal path,
processing a transmit RF signal to be transmitted by a wideband transmit signal path;
transmitting the transmit RF signal at a selected transmit frequency and a selected transmit polarization by a wideband transmitter;
controlling a plurality of beam forming circuits for performing signal processing and waveform generation; and
maximizing an effective radiated power (ERP) of the communication system within a predetermined ERP limit by switching the wideband transmitter between at least one of multiple transmit frequencies and multiple transmit polarizations to form an aggregate, time-averaged signal as the transmit RF signal, wherein maximizing the ERP of the communication system within a predetermined ERP limit further comprises:
determining a time to switch the selected transmit frequency, as a function of a transmission power of the wideband transmitter and the predetermined ERP limit, determining whether the wideband transmitter is using different polarization schemes, when it is the time to switch the selected transmit frequency;
switching the wideband transmitter to a new transmit frequency separated from the selected transmit frequency by a predetermined bandwidth, when it is determined that the wideband transmitter is not using different polarization schemes;
determining a time to switch the selected transmit polarization, as a function of a transmission power of the wideband transmitter and the predetermined ERP limit, when it is determined that the wideband transmitter is using different polarization schemes;
switching the wideband transmitter to the new transmit frequency, when it is not the time to switch the selected transmit polarization; and
switching the wideband transmitter to a new transmit polarization, when it is the time to switch the selected transmit polarization, to transmit the aggregate, time averaged low power signal at rotating polarizations and frequencies, as the transmit RF signal.

10. The RF communication method of claim 9 , wherein the time to switch the selected transmit frequency or to switch the selected transmit polarization is determined by the following equation:

∑
i

⁢

⁢

P
i

·

d
i

·

ρ
i

360
,
000
⁢

⁢
ms

=

2
⁢

⁢
W

(
1
)

where P i is transmitted power at duration d i and at polarization co

Assignees

• Raytheon Co

Inventors

• Marr Harry B
• Thompson Daniel

Classifications

• H04B1/04 Primary

  Circuits · CPC title

• H04W52/367 Primary

  Power values between minimum and maximum limits, e.g. dynamic range · CPC title

• G01S7/021

  Auxiliary means for detecting or identifying radar signals or the like, e.g. radar jamming signals · CPC title

• H04B2001/0416

  having gain or transmission power control · CPC title

• G01S7/006

  using shared front-end circuitry, e.g. antennas (G01S13/765, G01S13/825 take precedence) · CPC title