IP Library Granted Patent US 11,716,154
Granted Patent B2
US 11,716,154 · App. 17/872,964 · Granted Aug 1, 2023

Near zero intermediate frequency (NZIF) compensation of local oscillator leakage

Inventors: David Francois Jacquet (Vaulnaveys le Haut, FR); Marc Gens (Saint Martin D'Uriage, FR); Paul Lee Pearson (Biviers, FR); Pascal Triaire (Jarrie, FR)
Assignee: Space Exploration Technologies Corp.
H04B17/11H01Q3/2617H01Q3/38H01Q3/42H04B1/0082H04B1/38H04B17/12H04B17/19
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Quick Facts
Patent No.
US 11,716,154
App. No.
17/872,964
Granted
Aug 1, 2023
Kind
B2
Abstract

In an embodiment, a communications system includes a first transmitter including a digital beamforming baseband section configured to receive an input signal to be transmitted, the input signal at a baseband frequency, and a modulation section electrically coupled to the digital beamforming baseband section and a first antenna of a phased array antenna. The modulation section is configured to receive a local oscillator signal at a first local oscillator frequency and apply a baseband frequency shift to the input signal to generate a baseband frequency shifted input signal. The modulation section generates a modulated signal based on the input signal. The communication system includes a second transmitter included in a second IC chip of the plurality of IC chips electrically coupled to a second antenna and configured to provide a second modulated signal at the carrier frequency and a second LO leakage signal at a second local oscillator frequency.

Claims (31)

1. A communications system comprising:

a first transmitter included in a first integrated circuit (IC) chip of a plurality of IC chips including:

a digital beamforming baseband section configured to receive an input signal to be transmitted, the input signal at a baseband frequency; and

a modulation section electrically coupled to the digital beamforming baseband section and a first antenna of a phased array antenna, the modulation section configured to receive a local oscillator signal at a first local oscillator frequency, wherein:

the modulation section is configured apply a baseband frequency shift to the input signal to generate a baseband frequency shifted input signal;

the modulation section generates a modulated signal based on the input signal; and

the first antenna transmits the modulated signal at a carrier frequency and a local oscillator (LO) leakage signal at the first local oscillator frequency; and

a second transmitter included in a second IC chip of the plurality of IC chips electrically coupled to a second antenna of the phased array antenna, wherein the second transmitter is configured to provide a second modulated signal at the carrier frequency and a second LO leakage signal at a second local oscillator frequency different from the first local oscillator frequency to the second antenna for transmission.

2. The communications system of claim 1 , wherein:

a frequency of the baseband frequency shifted input signal is greater than zero hertz (Hz) or DC frequency; and

to generate the modulated signal based on the input signal, the modulation section is configured to up convert the baseband frequency shifted input signal based on the local oscillator signal.

3. The communications system of claim 2 , wherein the frequency of the baseband frequency shifted input signal comprises a near zero intermediate frequency (NZIF).

4. The communications system of claim 2 , wherein the first local oscillator frequency equals the carrier frequency minus the baseband frequency shift.

5. The communications system of claim 2 , wherein the second IC chip includes a second digital beamforming baseband section configured to:

receive a second input signal to be transmitted, the second input signal at the baseband frequency; and

apply a second baseband frequency shift to the second input signal to be transmitted to generate a second baseband frequency shifted input signal, wherein a frequency of the second baseband frequency shifted input signal is greater than zero Hz or DC frequency, wherein a baseband frequency separation between the baseband frequency shifted input signal and the second baseband frequency shifted input signal is equal to the baseband frequency shift.

6. The communications system of claim 2 , wherein the second modulated signal is based on a second input signal having a second baseband frequency shift different from the baseband frequency shift.

7. The communications system of claim 6 , wherein the second baseband frequency shift is a multiple of the baseband frequency shift.

8. The communications system of claim 7 , wherein the second local oscillator frequency equals the carrier frequency minus the second baseband frequency shift.

9. The communications system of claim 1 , wherein a maximum baseband frequency separation from the baseband frequency associated with an IC chip of the plurality of IC chips is less than a frequency bandwidth of the modulated signal.

10. The communications system of claim 1 , wherein the modulation section includes a first digital mixer and a second modulation section of the second transmitter includes a second digital mixer, and wherein the first digital mixer and the second digital mixer actuate in synchronization with each other.

11. The communications system of claim 10 , wherein the first digital mixer includes a baseband frequency shift generator electrically coupled to each of a first mixer associated with a complex-valued signal I component and a second mixer associated with a complex-valued signal Q component.

12. The communications system of claim 11 , wherein:

the first IC chip includes a first reference clock signal counter configured to count cycles of a reference clock;

the second IC chip includes a second reference clock signal counter configured to count cycles of the reference clock;

the first digital mixer is configured to actuate at a first particular value of the first reference clock signal counter; and

the second digital mixer is configured to actuate at a second particular value of the second reference clock signal counter, wherein the first particular value of the first reference clock signal counter and the second particular value of the second reference clock signal counter are equal.

13. The communications system of claim 1 , wherein the communications system comprises a satellite communications system.

14. The communications system of claim 1 , wherein the first transmitter is included in a first device of the communications system, wherein the communications system includes a receiver included in a second device, and wherein the receiver is configured to down convert the modulated signal received using a second local oscillator signal at a second local oscillator frequency, wherein the second local oscillator frequency is equal to the first local oscillator frequency.

15. The communications system of claim 1 , wherein the modulation section further comprises one or more digital beamforming components configured to encode the input signal to generate an encoded input signal, wherein the encoded input signal is modulated by the modulation section to generate the baseband frequency shifted input signal.

16. The communications system of claim 1 , wherein the first local oscillator frequency is selected to compensate for the baseband frequency shift to generate the modulated signal at the carrier frequency.

Assignments (6)
CERTIFICATE OF CONVERSION (STATE OF DELAWARE TO STATE OF TEXAS; NEW FILE NO.: 805421124; FILED : 02-14-2024) Recorded Feb 14, 2025
From: SPACE EXPLORATION TECHNOLOGIES CORP.
To: SPACE EXPLORATION TECHNOLOGIES CORP.
Reel/Frame 070631/0644 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Aug 5, 2022
From: STMICROELECTRONICS INTERNATIONAL N.V.
To: SPACE EXPLORATION TECHNOLOGIES CORP.
Reel/Frame 060738/0178 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 28, 2022
From: STMICROELECTRONICS (GRENOBLE 2) SAS
To: STMICROELECTRONICS INTERNATIONAL N.V.
Reel/Frame 060663/0365 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 28, 2022
From: STMICROELECTRONICS (ALPS) SAS
To: STMICROELECTRONICS INTERNATIONAL N.V.
Reel/Frame 060663/0390 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 27, 2022
From: JACQUET, DAVID FRANCOIS; PEARSON, PAUL LEE; GENS, MARC
To: STMICROELECTRONICS (GRENOBLE 2) SAS
Reel/Frame 060645/0139 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Jul 27, 2022
From: TRIAIRE, PASCAL
To: STMICROELECTRONICS (ALPS) SAS
Reel/Frame 060645/0228 →
Continuity (3)
Continuation 15931531 · May 13, 2020
Provisional Application 62847873 · May 14, 2019
Related Publication 20220368014A1 · Nov 17, 2022
Cited By (2)
US 12,278,433 US 12,627,051