Telecommunications – Transmitter – Power control – power supply – or bias voltage supply
Reexamination Certificate
2002-03-08
2004-11-23
Nguyen, Tony T. (Department: 2685)
Telecommunications
Transmitter
Power control, power supply, or bias voltage supply
C455S127500, C455S209000
Reexamination Certificate
active
06823179
ABSTRACT:
CROSS-REFERENCE TO RELATED APPLICATIONS
This application is based upon and claims the benefit of priority from the prior Japanese Patent Application No. 2001-065255, filed Mar. 8, 2001, the entire contents of which are incorporated herein by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a transmission apparatus, such as a radio telephone apparatus, and a transmission power detecting apparatus for detecting transmission power at such the transmission apparatus.
2. Description of the Related Art
FIG. 1
shows an arrangement of a radio transmitting section of a conventional radio telephone apparatus.
The radio telephone apparatus has a transmitting unit
1
and transmitting unit
2
. The transmission frequency of the transmitting unit
1
is a predetermined frequency f
1
. The transmission frequency of the transmitting unit
2
is a predetermined frequency f
2
higher than the frequency f
1
. The transmitting units
1
and
2
comprise modulators
1
a
and
2
a
, intermediate frequency band oscillators
1
b
and
2
b
, AGC amplifiers
1
c
and
2
c
, up-converters
1
d
and
2
d
, local oscillators
1
e
and
2
e
, bandpass filters
1
f
and
2
f
, and power amplifiers
1
g
and
2
g
, respectively.
The transmitting units
1
and
2
have their transmit operations controlled by a controller
3
to prevent both from simultaneously outputting their transmit signals. The transmit signals which are outputted from the transmitting units
1
and
2
are supplied, respectively through bandpass filters
4
and
5
, to a diplexer
6
and then to an antenna
7
where each transmit signal is radiated.
In this type of radio telephone apparatus, it is necessary to monitor transmission power so as to, for example, control it. To this end, a transmission power detecting apparatus
8
is provided. The transmission power detecting apparatus
8
has power detectors (DET)
8
a
and
8
b
, a rectifying diode
8
c
and smoothing capacitor
8
d.
The power detectors
8
a
and
8
b
detect the power levels of outputting signals from the transmitting units
1
and
2
. The power detectors
8
a
and
8
b
output detection signals representing the detecting power levels. Thus, the detection signal becomes an AC signal having its level varied in accordance with a variation in power level of the outputting signals from the transmitting units
1
and
2
.
The output terminals of the power detectors
8
a
and
8
b
are connected to the anode of the rectifying diode
8
c
. An output terminal T is connected to the cathode of the rectifying diode
8
c
, and the cathode of the rectifying diode
8
c
is grounded through the smoothing capacitor
8
d
. Thus, the detection signal outputted from either of the power detectors
8
a
and
8
b
is converted to a DC voltage by the rectifying diode
8
c
and smoothing capacitor
8
d
and outputted from the output terminal T.
In such transmission power detecting apparatus
8
, the transmitting units
1
and
2
perform no simultaneous transmit operation and, by utilizing this, a DC voltage conversion circuit is shared, the DC voltage conversion circuit comprising the rectifying diode
8
c
and smoothing capacitor
8
d
. By doing so, the circuit size is made smaller.
Incidentally, if the transmission power detecting apparatus
8
is so configured as set out above, a portion of the output signal of one of the transmitting units flows into the other transmitting system, thus producing a waste loss. As a result, the transmission power becomes smaller.
Further, there is sometimes the case where, depending upon a relation between the frequencies f
1
and f
2
, a high harmonic wave of one frequency occupies the same frequency band of the other frequency. In this case, there is a risk that the high harmonic wave flows into said other transmitting system will be supplied through the bandpass filter
4
or bandpass filter
5
to the antenna
7
and a high harmonic component will be radiated.
BRIEF SUMMARY OF THE INVENTION
The object of the present invention is to provide an apparatus which has a simple structure and can yet prevent transmitting systems from flowing unnecessary signals from one the other.
According to one aspect of the present invention, there is provided a transmission power detecting apparatus used for a transmission apparatus having a plurality of transmitting units with each transmission unit performing no simultaneous transmit operation relative to a remaining transmitting unit and adapted to detect a transmission power at the output of the transmission unit, comprising a plurality of detectors each configured to output a detection signal corresponding to an output power of a corresponding one of the transmitting units; a plurality of rectifiers each configured to receive an output of the corresponding detector at an input terminal and to allow a flow of only electric current from the input terminal toward an output terminal; and a smoothing device configured to smooth a signal supplied to one input terminal to which output terminals of the rectifiers are connected.
According to another aspect of the present invention, there is provided a transmission apparatus comprising a plurality of transmitting units each configured to perform no simultaneous transmit operation relative to a remaining transmitting unit; a plurality of detectors each configured to output a detection signal corresponding to an output power of the corresponding one of the transmitting units; a plurality of rectifiers each configured to receive an output of the corresponding detector at an input terminal and to allow only electric current from the input terminal toward an output terminal; a smoothing device configured to smooth a signal supplied one input terminal to which the output terminals of the rectifiers are connected; and a controller configured to control transmission power of the transmitting unit, which is performing the transmit operation, on the basis of a signal smoothed by the smoothing device.
Additional objects and advantages of the invention will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and obtained by means of the instrumentalities and combinations particularly pointed out hereinafter.
REFERENCES:
patent: 4573184 (1986-02-01), Tanaka et al.
patent: 5051666 (1991-09-01), Jensen
patent: 5585762 (1996-12-01), Dekker
Finnegan Henderson Farabow Garrett & Dunner L.L.P.
Kabushiki Kaisha Toshiba
Nguyen Tony T.
LandOfFree
Transmission power detecting apparatus and transmission... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Transmission power detecting apparatus and transmission..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Transmission power detecting apparatus and transmission... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3345346