JPH11163746A - Low power consumption radio transmitter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low power consumption radio transmitter the power consumption of which is reduced by eliminating wasteful power consumption. SOLUTION: This transmitter is provided with a high frequency amplifier 1 that produces a comparatively low power output and two high frequency amplifiers 2a, 2b that produce comparatively high power output. High frequency amplifiers 2a, 2b amplify transmission waves of different frequencies respectively, and the outputs of the high frequency amplifiers 2a, 2b are composited into one output by a combines 4a (or 4b). The output of the high frequency amplifier 1 and the combiner 4a (or 4b) is selected by an output changeover device 5a (5b) and sent from an antenna 7a (or 7b) as a radio wave. When a transmission wave of a single frequency is sent, the loss by the combiners 4a, 4b is not incurred, since the output of the high frequency amplifier 1 is given to the antenna 7a (or 7b).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low power consumption radio transmitter capable of selecting a state of transmitting a transmission wave of one frequency and a state of transmitting transmission waves of a plurality of frequencies simultaneously.

[0002]

2. Description of the Related Art Conventionally, there has been provided a radio transmitter capable of selecting a state of transmitting a transmission wave of one frequency and a state of transmitting transmission waves of a plurality of frequencies simultaneously. For example, the circuit configuration shown in FIG. 3 is capable of transmitting transmission waves of two frequencies simultaneously, and has two high-frequency amplifiers 2a and 2a for amplifying transmission waves of different frequencies.
b and the two outputs from both high-frequency amplifiers 2a and 2b are 1
And combiners 4a and 4b for combining the two.

Here, in the circuit configuration shown in FIG. 3, two antennas 7a and 7b are provided so that antenna switching diversity (at least one of spatial diversity, polarization diversity, and directivity diversity) is enabled. Antenna switches 3a and 3b are provided so that one of the antennas 7a and 7b having a good transmission state can be selected and a transmission wave can be transmitted. In addition, each antenna 7a, 7b
Is used not only for transmission but also for reception. The antennas 7a and 7b send the transmission waves from the combiners 4a and 4b to the antennas and send the reception waves from the antennas 7a and 7b to the reception circuit 8. The circulators 6a and 6b for sending are connected. The antenna switches 3a and 3b are connected to the receiving circuit 8
The switching is performed according to the reception state at. That is, in the receiving circuit 8, one of the antennas 7 having the better reception condition is used.
a (or 7b) is selected to receive a received wave, and the antenna 7a (or 7b) having a good reception state is determined to have a good transmission state, and the antenna 7a (or 7b) is selected so as to select the antenna 7a (or 7b). An instruction is given to the switches 3a and 3b. Thus, the receiving circuit 8 functions as an antenna selection control unit.

In the above configuration, the antenna switching devices 3a, 3
one antenna 7a (or 7b) selected by b
When the output of the combiner 4a (or 4b) is given, transmission waves of two frequencies can be transmitted simultaneously.
On the other hand, when transmitting only one frequency transmission wave, the output of one of the high-frequency amplifiers 2a (or 2b) is given to one of the antennas 7a (or 7b) selected by the antenna switches 3a and 3b. .

[0005]

By the way, in the above-described configuration, the combiners 4a and 4b are required to combine two signals into one signal when transmitting transmission waves of two frequencies simultaneously. . That is, the combiners 4a and 4b are unnecessary when transmitting only one frequency transmission wave. However, in the above-described configuration, the transmission waves output from the high-frequency amplifier 2a (or 2b) are combined even with one frequency. Vessel 4a (or 4
b).

FIG. 4 shows the transmission loss from the high-frequency amplifiers 2a and 2b to the antennas 7a and 7b. That is, there is a transmission loss of 3 dB or more in the combiners 4a and 4b. The high frequency amplifiers 2a and 2b are combined with the synthesizers 4a,
Since the output is set in consideration of the attenuation at 4b, a relatively high output is required for the high-frequency amplifiers 2a and 2b in order to output radio waves of a required output from the antennas 7a and 7b.

As described above, when transmitting a transmission wave of one frequency as described above, the transmission wave passes through the synthesizer 4a (or 4b) even though the combiners 4a and 4b are unnecessary. Since a relatively high output is used for the amplifiers 2a and 2b, wasteful power consumption results. The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-power-consumption wireless transmitter that reduces power consumption by reducing the useless power consumption described above.

[0008]

According to a first aspect of the present invention, there is provided an antenna, a plurality of relatively high-output first high-frequency amplifiers for amplifying transmission waves having different frequencies from each other, and a comparison apparatus for amplifying transmission waves. One second high-frequency amplifier having a very low output, a combiner for combining a plurality of outputs from each first high-frequency amplifier into one, and one of the output of the combiner and the second high-frequency amplifier. An output switching device which is selectively selected and provided to the antenna, and an output switching device which selects the output of the synthesizer when transmitting a plurality of frequencies simultaneously and selects the output of the second high-frequency amplifier when transmitting only one frequency. Output selection control means for giving an instruction. According to this configuration, when transmitting transmission waves of a plurality of frequencies at the same time, the output of the combiner that combines the outputs of the first high-frequency amplifiers having relatively high outputs into one is given to the antenna.
When transmitting only the transmission wave of the frequency, the output of the second high-frequency amplifier having a relatively low output is given to the antenna without passing through the combiner. No transmission loss occurs, and unnecessary power loss caused by the combiner when transmitting only one frequency in the conventional configuration can be reduced.

A second aspect of the present invention is the above-mentioned first aspect, further comprising a circulator for transmitting a transmission wave from the output switch to the antenna and transmitting a reception wave from the antenna to the receiving circuit. According to this configuration, the antenna is used for both transmission and reception. According to a third aspect of the present invention, in the first or the second aspect of the present invention, a plurality of antennas are provided, an antenna switch for selecting an antenna to be used for transmission from the antennas, and a transmission state monitoring and transmitting state. Antenna selection control means for giving an instruction to the antenna switching device so as to select an antenna having a good value. According to this configuration, an antenna having a good transmission state is selected from a plurality of antennas, so that transmission diversity is performed, and transmission conditions can be kept relatively good.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the embodiment described below, a case in which two antennas are used will be described. However, the present invention is not limited to this, and one antenna or three or more antennas may be used. If two or more antennas are provided, transmission diversity can be achieved.

In this embodiment, as shown in FIG. 1, the high-frequency amplifier 1 having a lower output than the high-frequency amplifiers 2a and 2b and the output of the high-frequency amplifier 1 are connected to two antennas in the conventional configuration shown in FIG. An antenna switch 3c for selecting which one of the antennas 7a and 7b is given;
7b is provided with output switches 5a and 5b for selectively outputting one of the outputs of the synthesizers 4a and 4b and the high-frequency amplifier 1. The antenna switches 3a, 3b, and 5c are selectively controlled by the receiving circuit 8 as in the conventional configuration. That is,
The receiving circuit 8 monitors the receiving state, and the antennas 7a and 7b having the better receiving state are adopted as receiving antennas. Also, the antenna switches 3a, 3b, 3c are switched so that the antenna 7a (or 7b) adopted as the receiving antenna is also used as the transmitting antenna. Here, the antenna switches 3a, 3b, 3c
Is constituted by a switch circuit for high frequency switching, and is selectively controlled by a switching signal from the receiving circuit 8.

Outputs of the high-frequency amplifiers 2a and 2b are input to combiners 4a and 4b through antenna switches 3a and 3b, respectively. The antenna switches 3a and 3b can select which one of the combiners 4a and 4b receives the output of each of the high-frequency amplifiers 2a and 2b, and each of the combiners 4a and 4b outputs the output of both high-frequency amplifiers 2a and 2b. Combine. When simultaneously transmitting the transmission waves of two frequencies output from the high-frequency amplifiers 2a and 2b, any one of the combiners 4a (or 4
In b), the outputs of both high-frequency amplifiers 2a and 2b are input simultaneously to combine both transmission waves.

On the other hand, the output of the high-frequency amplifier 1 is input to the antenna switch 3c. The antenna switch 3c is controlled by the receiving circuit 8 similarly to the antenna switches 3a and 3b. Output switches 5a and 5b are inserted between the antenna switch 3c and the antennas 7a and 7b together with the circulators 6a and 6b, respectively. The output switch 5a selectively inputs either the output of the combiner 4a or the output of the high-frequency amplifier 1 to the antenna 7a, and the output switch 5b controls the output of the combiner 4b to the antenna 7b and the high-frequency amplifier. 1 is selectively input. Output switch 5a, 5
b is controlled by the output control means. The output control means is, for example, 2
It is determined whether frequencies (that is, two channels) are used simultaneously or whether only one frequency needs to be used with less traffic.

With the above arrangement, when transmitting transmission waves of two frequencies at the same time, the combiners 4a and 4b are selected by the output switches 5a and 5b, and the high-frequency amplifiers 2a and 2b are selected.
b is output to the antenna switches 3a and 3b and the combiner 4
a and 4b, and then combined with one of the antennas 7
a and 7b. On the other hand, when transmitting only one frequency transmission wave, the output switching devices 5a and 5b select the antenna switching device 3c, so that the output of the high-frequency amplifier 1 is transmitted through the antenna switching device 3c to one of the antennas 7a and 7a.
7b. Since the combiners 4a and 4b are not used when transmitting only one frequency transmission wave, useless power consumption does not occur. As a result, the output of the high-frequency amplifier 1 is higher than that of the high-frequency amplifiers 2a and 2b. Small ones can be used. That is,
By selecting whether to supply power only to the high-frequency amplifiers 2a and 2b or to supply power only to the high-frequency amplifier 1 when transmitting the transmission wave of two frequencies and when transmitting only the transmission wave of one frequency (1) The power consumption when transmitting only one frequency transmission wave can be significantly reduced as compared with the case where two frequencies transmission waves are transmitted simultaneously.

In the present embodiment, when transmitting only one frequency transmission wave, the high-frequency amplifier 1 to the antenna 7
FIG. 2 shows transmission losses up to a and 7b. Now, in this embodiment, the output level (power) b of the circulator 6a (or 6b) when transmitting only one frequency transmission wave and the output level (power) of the circulator 6a (or 6b) in the conventional configuration shown in FIG. Assuming that (power) B is equal, in the present embodiment, the combiners 4a and 4b
, The output of the high-frequency amplifier 1 can be made smaller than the output of the high-frequency amplifiers 2a and 2b by the amount of no intervening signal.
By not using 4b, power consumption can be reduced. Other configurations and operations are the same as those of the conventional configuration shown in FIG. The present invention is applicable to any wireless transmitter that can use a plurality of frequencies simultaneously, such as a PHS base station. In addition, the technical idea of the present invention can be applied to a configuration in which two frequencies are simultaneously used by using antennas 7a and 7b that differ by one frequency.

[0016]

According to the first aspect of the present invention, there is provided an antenna, a plurality of first high-frequency amplifiers having relatively high outputs for amplifying transmission waves having different frequencies, and a relatively low output having a relatively high output for amplifying transmission waves. One second high-frequency amplifier, a combiner for combining a plurality of outputs from each first high-frequency amplifier into one, and selecting one of the output of the combiner and the second high-frequency amplifier for transmission And an output for giving an instruction to the output switch to select the output of the synthesizer when transmitting a plurality of frequencies simultaneously and to select the output of the second high-frequency amplifier when transmitting only one frequency. When transmitting transmission waves of a plurality of frequencies simultaneously, the output of a combiner that combines the outputs of the first high-frequency amplifiers having relatively high outputs into one is provided to the antenna. , 1 When transmitting only the transmission wave of the wave number, the output of the second high-frequency amplifier having a relatively low output is given to the antenna without passing through the combiner. There is an advantage that transmission loss does not occur and unnecessary power loss caused by the combiner when transmitting only one frequency in the conventional configuration can be reduced.

According to a second aspect of the present invention, a circulator for transmitting a transmission wave from an output switch to an antenna and transmitting a reception wave from the antenna to a receiving circuit is added, and the antenna is used for both transmission and reception. There is an advantage that can be. According to the third aspect of the present invention, a plurality of antennas are provided, and an antenna switch for selecting an antenna to be used for transmission from among the antennas, and a transmission state is monitored and an antenna having a good transmission state is selected. With the addition of the antenna selection control means for giving an instruction to the antenna switcher, an antenna having a good transmission state is selected from a plurality of antennas, so that transmission diversity is performed and transmission conditions are relatively good. There is an advantage that the state can be maintained.

[Brief description of the drawings]

FIG. 1 is a main part circuit diagram showing an embodiment of the present invention.

FIG. 2 is an operation explanatory view of the above.

FIG. 3 is a main part circuit diagram showing a conventional configuration.

FIG. 4 is an operation explanatory view of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 High frequency amplifier 2a, 2b High frequency amplifier 3a, 3b, 3c Antenna switch 4a, 4b Combiner 5a, 5b Output switch 6a, 6b Circulator 7a, 7b Antenna 8 Receiving circuit

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hideo Nabeshima 1048 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Works, Ltd. (72) Inventor Takashi Fujii 1048 Kadoma Kadoma, Kadoma City, Osaka Matsushita Electric Works, Ltd.

Claims (3)

[Claims] 1. An antenna, a plurality of relatively high-output first high-frequency amplifiers for respectively amplifying transmission waves of different frequencies, and one relatively low-output second high-frequency amplifier for amplifying transmission waves. An amplifier, a combiner for combining a plurality of outputs from each of the first high-frequency amplifiers into one, and an output switch for selecting one of the output of the combiner and the second high-frequency amplifier for transmission and providing the selected antenna to an antenna And output selection control means for instructing the output switch to select the output of the synthesizer when transmitting a plurality of frequencies simultaneously and to select the output of the second high-frequency amplifier when transmitting only one frequency. A low-power wireless transmitter. 2. The low power consumption wireless transmitter according to claim 1, further comprising a circulator for transmitting a transmission wave from the output switch to an antenna and transmitting a reception wave from the antenna to a receiving circuit. 3. An antenna switch provided with a plurality of antennas for selecting an antenna to be used for transmission from among the antennas, and an antenna switch for monitoring a transmission state and selecting an antenna having a good transmission state. 3. A low power consumption wireless transmitter according to claim 1, further comprising an antenna selection control means for giving an instruction to the wireless communication apparatus.