Demodulator stage for direct demodulation of a phase quadrature modulated signal and receiver including a demodulator stage of this kind

• US 5,760,645 A
• Filed: 11/12/1996
• Issued: 06/02/1998
• Est. Priority Date: 11/13/1995
• Status: Expired due to Fees

• Current Assignee: Alcatel Telspace
• Original Assignee: Alcatel Telspace
• Inventors: LeClerc, Gerard, Comte, Michel
• Primary Examiner(s): MIS, DAVID C
• Application Number:
  US08/744,146
• Time in Patent Office: 567 Days
• Field of Search: 329/304-310, 327/238, 327/254, 327/255, 333/100, 333/109, 333/117, 333/24 R, 333/24 C, 333/24.1-24.3, 455/313, 455/323, 455/325, 455/333, 455/293, 455/294, 455/214, 375/329-333
• US Class Current: 329/304
• CPC Class Codes: H04L 27/22 Demodulator circuits; Receiver circuits

Abstract

A demodulator stage for direct demodulation of a phase quadrature modulated signal provides two baseband signals and comprises a matched 900° coupler to which the modulated signal is fed and supplying two phase quadrature modulated signals. Two low-noise amplifiers with identical specifications each receive one of the phase quadrature modulated signals and supply an amplified signal. Two mixers each receive one of the amplified signals and a common local oscillator signal and supply the baseband signals. The 90° coupler, the low-noise amplifiers and the two mixers can be integrated into the same MMIC. One application is to a receiver for frequency evasive phase quadrature modulated signals.

Claims

1. A demodulator stage for direct demodulation of a phase quadrature modulated signal to provide two baseband signals and comprising:

a matched 90°

coupler to which said modulated signal is fed and supplying two phase quadrature modulated signals;

two low-noise amplifiers with identical specifications, each of said amplifiers receiving one of said phase quadrature modulated signals and supplying an amplified signal;

two mixers each receiving one of said amplified signals and a common local oscillator signal, said mixers supplying said baseband signals.

2. The demodulator stage claimed in claim 1 wherein said low-noise amplifiers are integrated into an MMIC.

3. The demodulator stage claimed in claim 2 wherein said 90°

coupler is integrated into said MMIC.

4. The demodulator stage claimed in claim 2 wherein said mixers are integrated into said MMIC.

5. A receiver for a phase quadrature modulated signal, said receiver comprising a demodulator stage for direct demodulation of a phase quadrature modulated signal to provide two baseband signals, said demodulator comprising:

a matched 90°

coupler to which said modulated signal is fed and supplying two phase quadrature modulated signals;

two low-noise amplifiers with identical specifications, each of said amplifiers receiving one of said phase quadrature modulated signals and supplying an amplified signal; and

two mixers each receiving one of said amplified signals and a common local oscillator signal, said mixers supplying said baseband signals.

6. A receiver as claimed in claim 5, wherein said low-noise amplifiers are integrated into an MMIC.

7. A receiver as claimed in claim 6, wherein said 90°

coupler is integrated into said MMIC.

8. A receiver as claimed in claim 8, wherein said mixers are integrated into said MMIC.