Power servo-loop, an RF signal amplifier circuit, and an RF signal transmitter fitted with such a circuit
AssigneeAlcatel
InventorsPierre Kolodziej, Mikael Pouliquen
Life of this patent
Estimating the term…
Abstract
The present invention relates to a power servo-loop in particular for controlling a power amplifier, the loop comprising a detection circuit (100) having coupling means (1) for taking off RF signals, and a detection unit (400) for delivering a detection signal (Vdet) partially representative of a first RF signal taken off by the coupling means. The detection circuit of the invention comprises, between the coupling means and the detection unit, detection control means (21, 22, 4) for substantially eliminating an “interfering” second RF signal also taken off by the coupling means, such that the detection signal is entirely representative of the first RF signal.
Claims17
1/ A power servo-loop (10) in particular for controlling a power amplifier (200), the servo-loop including a detection circuit (100), which comprises:
- coupling means (1) for taking off RF signals;
- and
- a detection unit (400) for delivering a detection signal (Vdet) partially representative of a first RF signal taken off by the coupling means;
- wherein the detection circuit further comprises, between the coupling means and the detection unit, detection control means (21, 22, 4) for substantially eliminating an “interfering” second RF signal also taken off by the coupling means so that the detection signal is entirely representative of the first RF signal.
2/ A power servo-loop (10) according to claim 1, wherein the detection circuit (100) comprises, at the output from the coupling means (1), first and second “output” branches (B1, B2) interconnected on a-“detection” branch (B3) including the detection unit (400), each output branch serving to convey a respective component (Iref1, Iref2) of the interference signal as taken off, and wherein the detection control means comprise first phase shifter means (21) inserted in the first output branch, and second phase shifter means (22) inserted in the second output branch, the first and second phase shifter means being suitable for inducing substantially opposite phase shifts to said components.
3/ A power servo-loop (10) according to claim 2, wherein each of the first and second phase shifter means (21, 22) comprises an inductor (210, 220) coupled with a capacitor (211, 221).
4/ A power servo-loop (10) according to claim 3, wherein the first output branch (B1) comprises a main branch (B1a) leading to the detection branch (B3) and including a first one of said inductors (210), together with a secondary branch (B1b) including a first one of said capacitors (211), which is connected between a ground plane (M1) and a connection point (P1) with the associated main branch, and wherein the second output branch (B2) comprises a main branch (B2a) leading to the detection branch (B3) and including the other one of said capacitors (221), which is substantially identical to the first capacitor (211), and a secondary branch (B2b) including the other one of said inductors (220), which is substantially identical to the first inductor (210), and which is connected between a ground plane (M2) and a connection point (P2) with the associated main branch.
5/ A power servo-loop (10) according to claim 2, wherein the detection control means comprise an attenuator (4) disposed in one of the output branches (B2a).
6/ A power servo-loop (10) according to claim 3, wherein the detection control means comprise an attenuator (4) disposed in one of the output branches (B2a).
7/ A power servo-loop (10) according to claim 4, wherein the detection control means comprise an attenuator (4) disposed in one of the output branches (B2a).
8/ A power servo-loop (10) according to claim 1, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
9/ A power servo-loop (10) according to claim 2, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
10/ A power servo-loop (10) according to claim 3, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
11/ A power servo-loop (10) according to claim 4, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
12/ A power servo-loop (10) according to claim 5, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
13/ A power servo-loop (10) according to claim 6, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
14/ A power servo-loop (10) according to claim 7, wherein the coupling means (1) comprise phase shifter means (11, 12, 13) suitable for phase shifting the taken-off RF signals.
15/ An RF signal amplification circuit (20) comprising a power amplifier (200) and a power servo-loop (10) according to claim 1 for said amplifier.
16/ An RF signal transmitter (500) comprising RF signal transmitter means (30) and fitted with an RF signal amplification circuit (20) according to claim 15.
17/ A transmitter (500) according to claim 16, the transmitter being selected from the group comprising:
- portable radio telephone stations;
- personal digital assistants;
- and portable computers.