JP3180750B2 - Portable radio - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a portable radio,
In particular, the present invention relates to a portable wireless device that improves the selectivity of a receiver against interference.

[0002]

2. Description of the Related Art Conventionally, devices are being incorporated into ICs (integrated circuits) in portable radios, and high-frequency devices such as low-noise amplifiers and mixers are also incorporated in ICs. As a result, in the conventional portable wireless device, a mixer capable of suppressing the image frequency with respect to the intermediate frequency can be easily configured. Furthermore, in the conventional portable radio,
In order to prevent the low noise amplifier and the mixer from saturating when the input signal has a strong electric field, a band pass filter for suppressing the receiver-to-spurious response is provided.

[0003]

However, in the conventional portable radio, the performance of the band-pass filter must be good, so that the price of the portable radio is high and the size of the portable radio is large. Problem.

It is an object of the present invention to provide a portable wireless device which is inexpensive and suitable for miniaturization.

[0005]

In order to solve the above-mentioned problems, the invention of the portable wireless device according to the first aspect of the present invention provides a portable wireless device in which
Low noise amplifier without over-filter and
The first mixer being used and immediately before the receive slot
Detects the electric field strength of the input signal received by the antenna
Input level detecting means for generating an electric field strength signal by
The electric field strength of the electric field strength signal from the input level detection means
Level comparison means for comparing with a threshold value, and this level comparison
The electric field intensity signal from the input level detecting means.
Low noise amplification when field strength is determined to be below threshold
Low voltage to the mixer and the first mixer and the level ratio
Comparing the electric field intensity signal from the input level detecting means by the comparing means.
Low noise increase when the electric field strength is judged to be higher than the threshold
Voltage controller for applying high voltage to breadth and first mixer
And characterized in that:

According to a second aspect of the present invention, there is provided the portable wireless communication system of the first aspect.
In the line machine, the frequency component between the low-noise amplifier and the antenna
And a first band-pass filter after the first mixer.
AGC amplifier connected to the filter and filter
Demodulator connected to the loop and connected to the demodulator
And an analog-to-digital converter.
Features.

[0007] The invention described in claim 3 is claim 1 or 2.
Portable wireless device, the portable wireless device further comprises a transmitter
It is characterized by having.

[0008] The invention according to claim 4 is the portable communication device according to claim 3.
In a wire machine, a transmitter is connected to a modulator and the modulator.
A second mixer, which is connected to the second mixer
A second bandpass filter and connected to the filter
Power amplification between preamplifier and amplifier and frequency divider
And a container.

According to a fifth aspect of the present invention, there is provided a portable wireless device with low noise.
A sound amplifier, a first mixer connected to the amplifier,
Received by the antenna just before the receiving slot
Generates electric field strength signal by detecting electric field strength of input signal
Input level detecting means, and
Level for comparing the electric field strength of the electric field strength signal with the threshold
Comparison means and input level detection by this level comparison means
The field strength of the field strength signal from the means is lower than the threshold
To the low noise amplifier and the first mixer.
Voltage and input level detection by level comparison means.
The electric field strength of the electric field strength signal from the output means is higher than the threshold.
To the low noise amplifier and the first mixer
A voltage control device for applying a high voltage;
And a third bandpass connected to the divider
And a first band after the first mixer.
Pass filter and AGC amplifier connected to the filter
And the demodulator connected to the amplifier and the demodulator
Analog-to-digital converter, and has modulation
And a second mixer connected to the modulator and a second mixer.
A second bandpass filter connected to the combiner;
Preamplifier connected to the
And a power amplifier between the distributor and the distributor.
You.

The invention according to claim 6 is the invention according to claims 1 to 5.
In any one of the portable radios, the input signal level is detected.
Means are the electric field strength of the input signal received by the antenna
To generate a field strength signal by detecting
And a detector for detecting the electric field strength signal.
It is characterized by being.

[0011]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a portable wireless device as a first embodiment of the present invention. As shown in FIG. 1, the portable wireless device of the present invention has an antenna 1
, A transmitter 2, a receiver 3, and an input level detection device 4
, A comparator 5, a voltage control device 6, and a control device 7.

The transmitter 2 includes a modulator 8 connected to the control device 7, a mixer 9 connected to the modulator 8, and a band-pass filter 10 connected to the mixer 9. A preamplifier 11 connected to the band-pass filter 10, a power amplifier 12 connected to the preamplifier 11, and a frequency divider 13 connected between the power amplifier 12 and the antenna 1. Have.

A modulation signal, which is a transmission signal emitted from the control device 7, enters a modulator 8. The modulator 8 modulates a modulation signal to generate a modulated wave. A transmission signal as a modulated wave from the modulator 8 is converted into a radio frequency by the mixer 9, passes through the band-pass filter 10,
The power is amplified by the power amplifier 12 to a specified output power. After that, the transmission signal passes through the frequency divider 13 and is radiated from the antenna 1.

The input level detecting device 4 includes a combiner 14
And a detector 15 connected to the coupler 14. The coupler 14 detects the electric field intensity (level) of the input signal applied to the antenna 1 and supplies the electric field intensity signal to the detector 15. The detector 15 detects the electric field intensity signal from the coupler 14, generates an envelope detection signal, and supplies the envelope detection signal to the comparator 5 and the control device 7. The comparator 5 includes a detector 15
Is compared with the reference signal from the control device 7 to generate an error signal and feed it back to the power amplifier 12. The power amplifier 12 receives the error signal from the comparator 5, controls the output voltage, and adjusts the level of the transmission signal radiated from the antenna 1 to a constant level.

The receiver 3 includes a frequency divider 13 connected to the antenna 1, a low noise amplifier 16 connected to the frequency divider 13, and a low noise amplifier 16 connected to the frequency divider 13.
, A band-pass filter 18 connected to the mixer 17, an AGC amplifier 19 connected to the band-pass filter 18,
It has a demodulator 20 connected to the GC amplifier 19, and an analog-digital converter 21 connected between the demodulator 20 and the control device 7.

The frequency divider 13 extracts a signal of only a reception band signal component from an input signal from the antenna 1. The input signal from the frequency divider 13 is a low noise amplifier 1
6 and the mixer 17 are converted into intermediate frequency signals having predetermined appropriate power. After that, the input signal passes through the band-pass filter 18, is amplified by the AGC pump 19, and is then demodulated by the demodulator 20. The input signal demodulated by the demodulator 20 is converted into a digital signal by an analog / digital converter 21 and supplied to the control device 7.

The voltage control device 6 includes a power supply voltage regulator 22, a DC / DC converter 23, the power supply voltage regulator 22 and the DC / DC converter 2
3 and a switch circuit 24 connected between the low noise amplifier 16 and the mixer 17. The switch circuit 24 is also connected to the control device 7 and receives the first and second voltage selection signals from the control device 7. The power supply voltage regulator 22 supplies a low voltage (for example, 3 V) to the low noise amplifier 16 and the mixer 17. DC
The / DC converter 23 supplies a high voltage (for example, 5 V) to the low noise amplifier 16 and the mixer 17. The switch circuit 24 responds to the first and second voltage selection signals from the control device 7
2 and DC / DC converter 23 are connected to low noise amplifier 16 and mixer 17.

The detector 15 of the input level detecting device 4
Detects an electric field intensity signal indicating the electric field intensity (level) of the input signal received by the antenna 1, generates an envelope detection signal, and supplies the envelope detection signal to the control device 7. This control device 7
The level of the envelope detection signal from the detector 15 is compared with a threshold value stored in advance. When the level of the envelope detection signal from the detector 15 is lower than the threshold value, the controller 7 generates a first voltage selection signal and supplies it to the switch circuit 24 of the voltage controller 6. Further, the control device 7 includes a detector 15
When the level of the envelope detection signal is higher than the threshold value, a second voltage selection signal is generated and supplied to the switch circuit 24 of the voltage control device 6. The switch circuit 24 connects the power supply voltage regulator 22 to the low noise amplifier 16 and the mixer 17 when receiving the first voltage selection signal from the control device 7, and applies a low voltage. The switch circuit 24 receives a DC / DC signal when receiving the second voltage selection signal from the control device 7.
Converter 23 is connected to low noise amplifier 16 and mixer 17 to provide a high voltage.

That is, when the electric field strength (level) of the input signal applied to the antenna 1 is lower than the threshold value, the voltage control device 6 applies a low voltage to the noise amplifier 16 and the mixer 17. When the electric field strength (level) of the input signal applied to the antenna 1 is higher than the threshold value, the voltage control device 6 applies a high voltage to the noise amplifier 16 and the mixer 17. Therefore, when the electric field strength (level) of the input signal applied to the antenna 1 is higher than the threshold value, a high voltage is applied to the noise amplifier 16 and the mixer 17, so that the input dynamic range is increased. This eliminates the need for a bandpass filter before the noise amplifier 16 and the mixer 17, that is, between the antenna 1 and the noise amplifier 16 and the mixer 17.

Next, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram illustrating a portable wireless device according to a second embodiment of the present invention. As shown in FIG. 2, a portable wireless device according to a second embodiment of the present invention includes an antenna 1, a noise amplifier 16 and a mixer 1 shown in FIG.
7, a band-pass filter 25 is added, and other configurations are the same as those of the portable wireless device according to the first embodiment of the present invention shown in FIG. The performance of the band-pass filter 25 in the portable wireless device according to the second embodiment of the present invention is such that when the electric field strength (level) of the input signal applied to the antenna 1 is higher than the threshold value, the noise amplifier 1
Since a high voltage is applied to the mixer 6 and the mixer 17, the input dynamic range becomes large, so that the performance of the band-pass filter in the conventional portable wireless device may be much lower.

[0021]

According to the portable radio of the present invention, the performance of the band-pass filter in front of the noise amplifier and the mixer may be low, and the band-pass filter is not required.
Low price and suitable for miniaturization.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a portable wireless device according to a first embodiment of the present invention.

FIG. 2 is a block diagram illustrating a portable wireless device according to a second embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Antenna 2 Transmitter 3 Receiver 4 Input level detection device 5 Comparator 6 Voltage controller 7 Controller 8 Modulator 9 Mixer 10 Bandpass filter 11 Preamplifier 12 Power amplifier 13 Frequency divider 14 Coupler 15 Detector 16 Low Noise amplifier 17 mixer 18 band-pass filter 19 AGC amplifier 20 demodulator 21 analog-to-digital converter 22 power supply voltage regulator 23 DC / DC converter 24 switch circuit 25 band-pass filter

Claims (6)

(57) [Claims] 1. Low noise without a band-pass filter at the preceding stage
A sound amplifier and a first mixer connected to the amplifier
An input level detecting means for detecting an electric field intensity of an input signal received by the antenna immediately before a receiving slot to generate an electric field intensity signal; and an electric field intensity and a threshold value of the electric field intensity signal from the input level detecting means. a level comparing means for comparing the bets, the low-noise amplifier and when the field strength of the electric field intensity signal from the input level detection means by the level comparing means is determined to be lower than the threshold value
Giving low voltage to the first mixer and the low - when the electric field intensity of the electric field intensity signal from the input level detection means is determined to be higher than the threshold by the level comparing means
A portable wireless device comprising: a sound amplifier and a voltage controller that applies a high voltage to the first mixer . 2. The frequency between the low-noise amplifier and the antenna.
A number divider, and a first zone after the first mixer.
Pass filter and AGC amplifier connected to the filter
And a demodulator connected to the amplifier, and
And the connected analog-to-digital converter.
The portable radio according to claim 1, wherein
Machine. 3. The portable wireless device further includes a transmitter.
The mobile phone according to claim 1 or 2, wherein
Wire machine. 4. The transmitter according to claim 1, further comprising a modulator connected to the modulator.
And a second mixer connected to the second mixer.
Connected second bandpass filter and connected to the filter
Between the preamplifier and the frequency divider
4. A power amplifier in between.
The portable radio described in 1. 5. A low noise amplifier and connected to the amplifier.
A first mixer, input level detecting means for detecting an electric field intensity of an input signal received by the antenna immediately before a receiving slot to generate an electric field intensity signal, and an electric field intensity signal from the input level detecting means. a level comparing means for comparing the electric field strength and the threshold, the low when the field strength of the electric field intensity signal from the input level detection means is determined to be lower than the threshold by the level comparison means
Providing a low voltage to the noise amplifier and the first mixer ; and
When the level comparing means determines that the electric field strength of the electric field strength signal from the input level detecting means is higher than a threshold value , a high voltage is applied to the low noise amplifier and the first mixer.
And a voltage control device that provides
A frequency divider and a third bandpass connected to the divider
And a first filter after the first mixer.
Bandpass filter and AGC connected to the filter
An amplifier; a demodulator connected to the amplifier;
Analog-to-digital converter connected to the
A modulator and a second mixer connected to the modulator
And a second bandpass filter connected to the second mixer.
A filter, a preamplifier connected to the filter,
A power amplifier between the amplifier and the frequency divider;
A portable wireless device characterized by having. 6. The input signal level detecting means detects a field strength of an input signal received by an antenna and generates a field strength signal, and is connected to the coupler and detects the field strength signal. The portable wireless device according to any one of claims 1 to 5 , further comprising a detector.