Gain and phase detector having dual logarithmic amplifiers

Details Gain and phase detector having dual logarithmic amplifiers Gain and phase detector having dual logarithmic amplifiers

2000-09-28

2004-11-23

Pascal, Robert (Department: 2829)

Electricity: measuring and testing

Measuring, testing, or sensing electricity, per se

Phase comparison

C324S1540PB

Reexamination Certificate

active

06822433

ABSTRACT:

BACKGROUND OF THE INVENTION
FIG. 1
illustrates a chain of gain stages
2
for a prior art logarithmic amplifier (log amp). A series of detector cells
4
combine the outputs from the gain stages to generate a logarithmic output V
OUT
. The gain stages are typically implemented as limiting amplifiers having the form A/0. That is, for small inputs, the gain stages have an incremental gain of A, but at a certain point, the output is limited, and the incremental gain becomes zero as shown in FIG.
2
. The response of the system of
FIG. 1
is:
V
OUT
=
V
y
⁢
log
⁡
(
V
IN
V
x
)
(
Eq
.
 
⁢
1
)
where V
y
and V
x
are parameters that are built into the system and define its calibration. A Referring to
FIG. 3
, V
y
scales the slope, and V
x
is the intercept along the horizontal axis. The intercept is usually an extrapolated parameter because in practice, it is unlikely that the output will drop below the nose floor as shown with the broken line in FIG.
3
. Both V
x
and V
y
may be temperature dependent, and must therefore be temperature compensated to maintain the accuracy of the log amp. These are matters that have received close attention in prior invention.


REFERENCES:
patent: 4131254 (1978-12-01), Underwood
patent: 4261056 (1981-04-01), Barnett et al.
patent: 4538105 (1985-08-01), Ausschnitt
patent: 4568978 (1986-02-01), Cosh
patent: 4906836 (1990-03-01), Yamashita et al.
patent: 5019786 (1991-05-01), Fairley et al.
patent: 5508610 (1996-04-01), Feeney et al.
patent: 5530349 (1996-06-01), Lopez et al.
patent: 5534854 (1996-07-01), Bradbury et al.
patent: 5731698 (1998-03-01), Fujii et al.
patent: 5767780 (1998-06-01), Smith et al.
patent: 5789927 (1998-08-01), Belcher
patent: 5805011 (1998-09-01), Comino
patent: 5865632 (1999-02-01), Iwasaki
patent: 6424212 (2002-07-01), Brandt
patent: 6486679 (2002-11-01), Holt
patent: 362179635 (1987-08-01), None
The New IEEE Standard Dictionary of Electrical and Electronics Terms, Fifth Edition, IEEE Std 100-1992, cover pages (front and back) and pp. 717 and 916, Jan. 15, 1993.
Monolithic Logarithmic Amplifiersarticle by Barrie Gilbert, Analog Devices, Inc., Aug. 1994, pp. 1-122.

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