JPH11331029A - Two-way radio communication equipment and pcmcia card type two-way radio communication equipment using it - Google Patents

Abstract

PROBLEM TO BE SOLVED: To satisfy miniaturization and low cost at the same time by reducing transmission spurious radiation from a two-way radio communication equipment and improving the reception sensitivity. SOLUTION: The equipment is provided with a band pass filter 11, a low noise amplifier connected between the filter 11 and an input terminal 51 of an orthogonal demodulator 14, an attenuator 19 connected between the filter 11 and an output terminal 54 of an orthogonal modulator 17, a PLL oscillator 18 whose output terminal connects to an oscillation input terminal 52 of the orthogonal demodulator 17 and connecting to an oscillation input terminal 53 of the orthogonal demodulator 17, a 1st low pass filter 15 connected between a base band output terminal 56 of the orthogonal demodulator 14 and a base band input terminal of a signal processor 30, a 2nd low pass filter 16 connected between a base band input terminal 55 of the orthogonal demodulator 17 and a base band output terminal of the signal processor 30, and a data output terminal 21 and a data input terminal 20 connecting to the signal processor 30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-way wireless communication device used for information communication equipment such as a personal computer and a printer, and a PCMCIA card-type two-way wireless communication device using the same.

[0002]

2. Description of the Related Art Conventionally, this type of two-way wireless communication apparatus has the configuration shown in FIG. 6, reference numeral 81 denotes another PLL oscillator, 82 denotes a transmission amplifier, 83 denotes a transmission mixer, 84 denotes a transmission IF filter, 85 denotes a reception IF filter, and 86 denotes a reception mixer, and a radio frequency input or output from the antenna terminal 10 Is converted to another IF frequency.

[0003]

SUMMARY OF THE INVENTION A radio frequency is connected to another IF.
In the case where the frequency is converted, the circuit configuration scale becomes complicated, and it is difficult to reduce the size or the cost of the bidirectional wireless communication device. In this two-way wireless communication device, a reduction in the size of the PCMCIA card is required. According to the present invention, a radio circuit is configured by a direct conversion method that directly processes a radio signal without converting a radio frequency to another IF frequency, and the radio frequency and the oscillation frequency of a PLL oscillator are set to different frequencies, thereby extending a reach. It is an object of the present invention to realize an improved interference elimination characteristic and to simultaneously achieve the miniaturization and cost reduction of a two-way wireless communication device.

[0004]

In order to solve this problem, a two-way wireless communication apparatus according to the present invention comprises a band-pass filter connected between an antenna terminal and an antenna terminal side of an antenna changeover switch; A low-noise amplifier connected between the receiving terminal of the antenna changeover switch and the input terminal of the quadrature demodulator, and an attenuator connected between the transmission terminal of the antenna changeover switch and the output terminal of the quadrature modulator; A PLL oscillator having an output terminal connected to the oscillation input terminal of the quadrature demodulator and connected to the oscillation input terminal of the quadrature modulator; and a baseband output terminal of the quadrature demodulator and a baseband input terminal of the signal processor. A first low-pass filter connected therebetween, a baseband input terminal of the quadrature modulator, and a baseband output of the signal processor Those having a second low pass filter connected between the child, the connected data output terminal and a data input terminal to the signal processor.

Further, a PCMCIA card type bidirectional wireless communication apparatus according to the present invention comprises the bidirectional wireless communication apparatus according to claim 1 formed on one surface of a first double-sided multilayer substrate, and the first double-sided multilayer communication apparatus. The other surface of the substrate is grounded, a planar antenna is formed on a second substrate, and the first double-sided multilayer substrate and the second substrate are arranged so as to overlap in a direction perpendicular to the plane of the substrate. Claim 1
The two-way wireless communication device according to claim 1 is configured on one surface of a first double-sided multilayer substrate, the other surface of the first double-sided multilayer substrate is grounded, and the loop antenna is configured as an extension. It is also what to say. As a result, it is possible to increase the reach of the two-way wireless communication device and improve the interference rejection characteristics, and simultaneously achieve downsizing and cost reduction.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention is directed to a band-pass filter connected between an antenna terminal and an antenna terminal side of an antenna changeover switch, and a filter which is orthogonal to a reception terminal of the antenna changeover switch. A low-noise amplifier connected between an input terminal of a demodulator, an attenuator connected between a transmission terminal of the antenna switch and an output terminal of a quadrature modulator, and an output terminal of the attenuator connected to the quadrature demodulator. A PLL oscillator connected to an oscillation input terminal and connected to an oscillation input terminal of the quadrature modulator, and a first oscillator connected between a baseband output terminal of the quadrature demodulator and a baseband input terminal of the signal processor. A low-pass filter, and a second low-pass filter connected between a baseband input terminal of the quadrature modulator and a baseband output terminal of the signal processor. And filter, which has a connected data output terminal and a data input terminal to the signal processor, has the effect of reducing the size and cost of the two-way wireless communication device at the same time.

According to a second aspect of the present invention, the radio frequency (fc) output or input from the antenna terminal is different from the oscillation frequency (fo) of the PLL oscillator. Device.
This has the effect of increasing the reach of the two-way wireless communication device and improving the interference rejection characteristics.

According to a third aspect of the present invention, there is provided the bidirectional wireless communication apparatus according to the first aspect, wherein the reference signal required for the PLL oscillator and the system clock required for the signal processor are supplied from the same reference signal generator. This has the effect of simultaneously realizing size reduction and cost reduction of the two-way wireless communication device.

According to a fourth aspect of the present invention, the bidirectional wireless communication device according to the first aspect is formed on one surface of a first double-sided multilayer substrate, and the other surface of the first double-sided multilayer substrate is grounded. A PCMCIA card-type bidirectional wireless communication device in which a planar antenna is formed on a second substrate, and the first double-sided multilayer substrate and the second substrate are arranged so as to overlap in a direction perpendicular to the plane of the substrate. This has the effect that the antenna can be built in the PCMCIA card type bidirectional wireless communication device.

According to a fifth aspect of the present invention, the bidirectional wireless communication apparatus according to the first aspect is formed on one surface of a first double-sided multilayer substrate, and the other surface of the first double-sided multilayer substrate is grounded. And a PCMCIA in which a loop antenna is configured as an extension unit
Card type two-way wireless communication device, PCM
The CIA card type two-way wireless communication device has the effect of increasing the reach and improving the interference rejection characteristics.

Hereinafter, an embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. (Embodiment 1) FIG. 1 is an electric circuit diagram of a two-way wireless communication apparatus according to a first embodiment of the present invention. The band-pass filter 11 is connected between the antenna terminal 10 and the antenna terminal 12a of the antenna changeover switch 12, selectively passes only a frequency necessary for wireless communication, removes unnecessary transmission high-frequency waves, and eliminates unnecessary It is provided in order to remove unnecessary reception interference waves. In the present embodiment, the band-pass filter 11 is configured by a chip coil and a chip capacitor, but may be a SAW filter or a dielectric filter.

The antenna changeover switch 12 includes an antenna terminal 12a, a reception terminal 12b, and a transmission terminal 12c, and operates in synchronization with the timing at which the transmission operation and the reception operation of the system are switched to switch the transmission path and the reception path. In the present embodiment, the antenna changeover switch 12 is configured by an SPDT switch made of GaAs, and the current consumption is reduced by the antenna changeover operation by voltage control. Note that the antenna changeover switch 12 may be configured by a PIN diode, but in this case, current control is performed and current consumption is required. The low-noise amplifier 13 is provided to reduce the noise in the reception path, and improves the reception sensitivity of the system. In the present embodiment, the forward power gain of the low noise amplifier 13 is set to 22 d
B, the noise figure is 1.5 dB, and the system reception sensitivity is improved by 20 dB or more as compared with the case where the low noise amplifier 13 is not provided. The power supply of the low noise amplifier 13 is operated in conjunction with the antenna changeover switch 12,
At the time of transmission, the power supply of the low noise amplifier 13 is turned off to reduce the current consumption of the system.

The quadrature demodulator 14 includes a first mixer 71, a second mixer 72, and a first 90-degree phase shifter 73. In the present embodiment, the quadrature demodulator 14 is a semiconductor integrated device, and the power supply of the quadrature demodulator 14 is interlocked with the antenna changeover switch 12 so as to operate only at the time of reception similarly to the power supply of the low noise amplifier 13. The current consumption is reduced. The received signal input from the input terminal 51 of the quadrature demodulator 14 is input to a first mixer 71 and a second mixer 72, and quadrature demodulated. The local signal from the PLL oscillator 18 input from the oscillation input terminal 52 of the quadrature demodulator 14 is input to the first mixer 71 in the same phase, and the first 90-degree phase shifter 73 is input to the second mixer 72. The data is input in a 90-degree shifted state. The outputs multiplied by the first mixer 71 and the second mixer 72 are output from the quadrature demodulator 1 while maintaining a state where the phases are mutually orthogonal (shifted by 90 degrees).
4 is output from the baseband output terminal 56 and is input to the signal processor 30 via the first low-pass filter 15. The signal-processed data is output from the data output terminal 21 of the signal processor 30.

In this embodiment, it is added that the signal processor 30 is configured as a circuit for modulating and demodulating a digital signal composed of a spread spectrum correlator. Further, the first low-pass filter 15 is configured so that the cut-off frequency is half the frequency of the transmission speed, and the cut-off frequency of the second low-pass filter 16 is also the first low-pass filter. Same as 15.
By providing the same roll-off characteristics on the receiving side and the transmitting side in this way, consideration is given to minimizing the spatial interference of wireless communication. On the other hand, the signal input from the data input terminal 20 of the signal processor 30 is spread-modulated by the signal processor 30 and input to the baseband input terminal 55 of the quadrature modulator 17 via the second low-pass filter 16. You. The quadrature modulator 17 includes a third mixer 74 and a fourth mixer 75
And a second 90-degree phase shifter 76.

In the present embodiment, the quadrature modulator 17 is a semiconductor integrated device, and the power supply of the quadrature modulator 17 is also linked with the antenna switch 12 so as to operate only at the time of transmission, thereby reducing the current consumption of the system. ing. The transmission signal input from the baseband input terminal 55 of the quadrature modulator 17 is input to the third mixer 74 and the fourth mixer 75 and quadrature modulated. The local signal from the PLL oscillator 18 input from the oscillation input terminal 53 of the quadrature modulator 17 is input to the fourth mixer 75 in the same phase, and the third mixer 74
Is input in a 90-degree shifted state after passing through the second 90-degree phase shifter 76. The outputs multiplied by the third mixer 74 and the fourth mixer 75 are added while maintaining a state where the phases are orthogonal (shifted by 90 degrees) to each other, and the quadrature modulator 1
7 is output from the output terminal 54. The output terminal 54 of the quadrature modulator 17 is connected to the transmission terminal of the antenna changeover switch 12 via the attenuator 19, and the transmission power of the transmission signal output from the output terminal 54 of the quadrature modulator 17 is adjusted by the attenuator 19. We are implementing.

In this embodiment, as shown in FIG. 1, a direct conversion system for directly quadrature modulating and demodulating a radio frequency is used. This can be realized by selecting a radio frequency in a weak band. In this state, the output of the PLL oscillator 18 is connected to the oscillation input terminal 52 of the quadrature demodulator 14 and to the oscillation input terminal 53 of the quadrature modulator 17. In this way, the local frequency required for transmission and reception can be shared, and as a result, the number of parts and cost of the two-way wireless communication device can be significantly reduced.

In FIG. 1, when the radio frequency and the output frequency of the PLL oscillator 18 are the same frequency, the PLL oscillator 1
The output 8 may be mixed into the receiving side from the antenna terminal 10 to degrade the receiving sensitivity. It is described that this problem can be avoided in other embodiments.

First, the oscillation frequency of the PLL oscillator 18 (f
o) is configured to be twice the radio frequency (fc). The oscillation input terminal 52 of the quadrature demodulator 14 and the quadrature modulator 1
7, an oscillation input terminal 53 is provided with a flip-flop circuit,
The input fo is divided by two. fo and fo divided by 2
Is a signal shifted by 90 degrees, so that the quadrature demodulator 14 and the quadrature modulator 17
Can be operated respectively. Actually, this flip-flop circuit is constituted by a semiconductor integrated device incorporated in the oscillation input terminal 52 of the quadrature demodulator 14 and the oscillation input terminal 53 of the quadrature modulator 17, respectively. In this way, even if the oscillation frequency of the PLL oscillator 18 is mixed from the antenna terminal 10 to the receiving side, the frequency becomes different from that of the received signal, and as a result, the problem that the receiving sensitivity is deteriorated can be prevented. .

(Embodiment 2) FIG. 2 is an electric circuit diagram of a two-way wireless communication apparatus showing a second embodiment of the present invention. The reference signal of the PLL device 32 of the PLL oscillator 18 of FIG. 2 and the system clock of the signal processor 30 are supplied from the same reference signal generator 33. The reference signal generator 33 is a TOXO, and operates stably with respect to changes in the temperature environment. Reference signal generator 33
Is an output frequency near the upper limit that operates as a reference signal of the PLL device 32.
The harmonic signal components output from the ASIC are reduced as much as possible.

Note that the comparison frequency of the PLL device 32 is also PL
It should be added that the frequency near the upper limit at which the L device 32 can divide frequency is selected. Further, the program counter of the PLL device 32 is realized by an internal write type, so that unnecessary data input lines are deleted. With this configuration, it is possible to simplify the control line and reduce the number of components.

(Embodiment 3) FIG. 3 is a mounting layout diagram of a two-way wireless communication apparatus according to a third embodiment of the present invention. As shown in FIG. 3, the PLL oscillator 18, the PLL device 32, and the reference signal generator 33 are arranged at a substantially central position of the two-way wireless communication device 60, and are mounted so as to be surrounded by a ground pattern. With this arrangement, the PLL oscillator 18 and the reference signal generator 33
Of the bidirectional wireless communication device 60 is reduced, and as a result, the reception sensitivity characteristic is improved.

Although the components are mounted on only one surface of the double-sided board in the present embodiment, it is added that the components may be mounted on the other side of the double-sided board.

(Embodiment 4) FIG. 4 is a configuration diagram of a PCMCIA card type two-way wireless communication apparatus showing a fourth embodiment of the present invention. As shown in FIG. 4, a bidirectional wireless communication device 6 in which components are mounted on one surface of a double-sided multilayer substrate 77 and the other surface of the double-sided multilayer substrate 77 is grounded.
0 and the planar antenna 90 are fixed via a spacer 88. With this arrangement, the ground pattern formed on the other surface of the double-sided multilayer substrate 77 between the component mounting surface formed on one surface of the bidirectional wireless communication device 60 and the planar antenna 90 serves as an electrical shield. Therefore, the bidirectional wireless communication device 60 operates stably without mixing unnecessary signals from the antenna, and as a result, the PCMCIA
The antenna can be built in the card size, and the size of the device can be reduced.

(Embodiment 5) FIG. 5 is a block diagram of a PCMCIA card type bidirectional wireless communication apparatus showing a fifth embodiment of the present invention. As shown in FIG. 5, the loop antenna 9 is extended to the outside of the two-way wireless communication device 60.
9 is connected. With this configuration,
It is possible to reduce the thickness of the PCMCIA card type bidirectional wireless communication device. The loop antenna 99 is
It should be added that it may be detachable or integrated.

[0025]

As described above, according to the present invention, a band-pass filter connected between an antenna terminal and an antenna terminal side of an antenna changeover switch, a reception terminal of the antenna changeover switch and an input of a quadrature demodulator are provided. A low-noise amplifier connected between the output terminal of the quadrature modulator, an attenuator connected between the transmission terminal of the antenna changeover switch and the output terminal of the quadrature modulator, and an output terminal connected to the oscillation input terminal of the quadrature demodulator. A first low-pass filter connected between a PLL oscillator connected to an oscillation input terminal of the quadrature modulator and a baseband output terminal of the quadrature demodulator and a baseband input terminal of a signal processor; When,
A second low-pass filter connected between a baseband input terminal of the quadrature modulator and a baseband output terminal of the signal processor; a data output terminal and a data input terminal connected to the signal processor; , Which makes it possible to reduce the size and cost of the two-way wireless communication device,
An advantageous effect is obtained in that the problem that the transmission spurious characteristics and the reception sensitivity characteristics are deteriorated can be solved.

[Brief description of the drawings]

FIG. 1 is an electric circuit diagram showing a bidirectional wireless communication device according to a first embodiment of the present invention.

FIG. 2 is an electric circuit diagram showing a two-way wireless communication device according to a second embodiment of the present invention;

FIG. 3 is a mounting layout diagram showing a bidirectional wireless communication device according to a third embodiment of the present invention;

FIG. 4 shows a PCMCIA according to a fourth embodiment of the present invention.
Structural diagram showing a card-type two-way wireless communication device

FIG. 5 shows a PCMCIA according to a fifth embodiment of the present invention.
Structural diagram showing a card-type two-way wireless communication device

FIG. 6 is an electric circuit diagram showing a conventional two-way wireless communication device.

[Explanation of symbols]

 Reference Signs List 10 antenna terminal 11 band-pass filter 12 antenna switch 12a antenna terminal of antenna switch 12b reception terminal of antenna switch 12c transmission terminal of antenna switch 13 low-noise amplifier 14 quadrature demodulator 15 first low-pass filter 16th 2 low-pass filter 17 quadrature modulator 18 PLL oscillator 19 attenuator 20 data input terminal 21 data output terminal 30 signal processor 32 PLL device 33 reference signal generator 51 quadrature demodulator input terminal 52 quadrature demodulator oscillation input terminal 53 Oscillation input terminal of quadrature modulator 54 Output terminal of quadrature modulator 55 Baseband input terminal of quadrature modulator 56 Baseband output terminal of quadrature demodulator 60 Bidirectional wireless communication device 77 Double-sided multilayer board 81 PLL oscillator 2 transmission amplifier 83 transmitting mixer 84 sends IF filter 85 receives the IF filter 86 receiving mixer 88 spacer 90 planar antenna 99 loop antenna

Claims (5)

[Claims] 1. A bandpass filter connected between an antenna terminal and an antenna terminal side of an antenna changeover switch, and low noise connected between a reception terminal of the antenna changeover switch and an input terminal of a quadrature demodulator. An amplifier,
An attenuator connected between a transmission terminal of the antenna changeover switch and an output terminal of the quadrature modulator, and an output terminal connected to an oscillation input terminal of the quadrature demodulator and connected to an oscillation input terminal of the quadrature modulator; Connected to a baseband output terminal of the quadrature demodulator and a baseband input terminal of the signal processor.
A low-pass filter, a second low-pass filter connected between a baseband input terminal of the quadrature modulator and a baseband output terminal of the signal processor, and a second low-pass filter connected to the signal processor. A bidirectional wireless communication device having a data output terminal and a data input terminal. 2. A radio frequency (fc) output or input from an antenna terminal and an oscillation frequency (f) of a PLL oscillator.
2. The two-way wireless communication apparatus according to claim 1, wherein o) is configured with different frequencies. 3. The two-way wireless communication apparatus according to claim 1, wherein the reference signal required for the PLL oscillator and the system clock required for the signal processor are supplied from the same reference signal generator. 4. The two-way wireless communication apparatus according to claim 1, wherein the two-way wireless communication device is formed on one surface of a first double-sided multilayer substrate, and the other surface of the first double-sided multilayer substrate is grounded. A planar antenna, the first double-sided multilayer substrate and the second
PCMCIA card type two-way wireless communication apparatus, wherein the PCMCIA card type bidirectional wireless communication apparatus is disposed so as to overlap with the substrate in a direction perpendicular to the substrate plane. 5. A two-way wireless communication apparatus according to claim 1, wherein said two-sided multilayer board is provided on one surface of said first double-sided multilayer board, and the other side of said first double-sided multilayer board is grounded. A PCMCIA card type bidirectional wireless communication device configured as an extension unit.