JPH08330845A - Plural frequency band voltage control oscillator and time division multiplex fdd/tdd dual mode radio machine using the same - Google Patents

Abstract

PURPOSE: To provide an inexpensive plural frequency band voltage control oscillator which requires only a small circuit scale and space. CONSTITUTION: When a band change-over switch 15 is turned off, the other end of a distribution constant line 7 is equivalently open, and a resonance circuit resonates in a high frequency band in the tip open 1/2 wavelength resonance mode of the distribution constant line 7 and an oscillation circuit including a transistor 20 is oscillated. When the band change-over switch 15 is turned on, the other end of the distribution constant line 7 is grounded and the resonance circuit resonance in a low frequency band in the tip short circuit 1/4 wavelength resonance mode of the distribution constant line 7. The capacity of a varactor diode 5 is changed by frequency variable voltage VT given from a frequency variable voltage terminal 1, and the oscillation frequency of the oscillation circuit including the transistor 20 is finely adjusted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plurality of frequency band voltage controlled oscillators capable of switching and using at least two frequency bands, and time division multiplexing (hereinafter referred to as T).
There are two types of radios, a DMA (abbreviated as DMA) type and using different frequencies for transmission and reception (hereinafter abbreviated as FDD), and a method in which transmission and reception are separated by time division (hereinafter abbreviated as TDD). The present invention relates to a time division multiplexing FDD / TDD dual mode radio that can use the above two methods in one device.

[0002]

2. Description of the Related Art In recent years, a voltage controlled oscillator (hereinafter referred to as VCO) is used in various circuits such as PLL since it can freely change the frequency by changing the voltage applied to a variable capacitance diode. Among them, a multi-frequency band voltage controlled oscillator, which can be used over at least two frequency bands, is often used especially for a radio device using a plurality of frequency bands.

A conventional multi-frequency band voltage controlled oscillator capable of switching and using two frequency bands will be described below with reference to the drawings.

FIG. 9 is a block diagram of a conventional multi-frequency band voltage controlled oscillator. In the figure, a voltage-controlled oscillator 91 (VCO1) that oscillates a first frequency band and a voltage-controlled oscillator 92 (VCO2) that oscillates a second frequency band are provided respectively, and after oscillating in each band, The switch 93 selects the oscillation output of any frequency band and outputs it to the output terminal.

Next, a time division multiplexing FDD / TDD dual mode radio using such a conventional frequency band voltage controlled oscillator will be described with reference to FIG. 10 which is a block diagram thereof. First, in the TDD mode, mode changeover switches 129, 130, 131 and 1
32 to 129a, 130a, 131a, and 132
Switch to the a side. The high-frequency signal input from the antenna 101 during reception is the antenna switch 102.
Is connected to the 102r side, the high-frequency bandpass filter 103a passes through the mode change-over switches 129 and 129a, and 1895.15 to 1917.95MH.
The receiving frequency fRa of the local station of z is selected and the high frequency amplifier 10
4a, is amplified here, and is further increased in selectivity by the high-frequency bandpass filter 105a, and then inputted to the converter 106a, where the first local oscillator 108 is inputted.
1646.85-166.65MHz input from a
248.3M when mixed with the first local oscillation frequency fL1a of
The first intermediate frequency fR1a is converted into the first intermediate frequency fR1a, and the selectivity is increased by the first intermediate frequency bandpass filter 109a.
Amplified by the intermediate frequency amplifier 110a, and further 259.1
Second local oscillator 1 having a second local oscillation frequency fL2b of MHz
The oscillation frequency from 12b is mixed with the converter 111a and converted into the second intermediate frequency fR2a of 10.8 MHz, the selectivity is increased by the second intermediate frequency bandpass filter 115a, and the demodulator 116a demodulates the received output. obtain.

During transmission, the second local oscillator 112b outputs the second
The transmission intermediate frequency fT1 obtained by digitally modulating the output of the local oscillation frequency fL2b, 259.1 MHz with the modulation signals I and Q by the modulator 119 is amplified by the transmission intermediate frequency amplifier 120, and the selectivity is increased by the transmission intermediate frequency bandpass filter 121. Then contact 1 of the mode changeover switch 130
30a to 1636.05 to 1658.85 MH in a frequency range different from that at the time of reception from the first local oscillator 108a.
The first local oscillation frequency fL1a of z (this switching is performed by a transmission / reception controller not shown) is input to the converter 122, where 1895.15-191.
It is converted to a high frequency signal of 7.95 MHz of the transmission frequency fT of the own station, and the selectivity is increased by the high frequency band pass filter 123a from the contact 132a of the mode switch 132,
After being amplified by the high-frequency amplifier 124a and the high-frequency power amplifier 125a and having increased selectivity by the high-frequency bandpass filter 126a, the contact 3 of the mode changeover switch 131.
1a, contact point 102t of antenna changeover switch 102
Through the antenna 101. The antenna changeover switch 102 is switched at high speed between reception and transmission. For example, when four radios share the same frequency, one frame is set to 5 msec, and this is 625 μs.
divided into 8 time slots of ec, one radio transmits at the first slot and receives at the fifth slot,
Wait for the remaining 6 slots. During that time, other wireless devices can perform simultaneous transmission and reception by repeating transmission and reception. When receiving, each device (amplifier,
The operation of a converter, a modulator, etc.) is turned off by a transmission / reception controller (not shown), and each device of the receiving circuit is also turned off during transmission.

Next, the FDD mode will be described. Mode changeover switches 129, 130, 131 and 1
32 to 129b, 130b, 131b and 132b
And the mode / transmission / reception switch 133 is switched to the contact 133b. Antenna 1 for reception
The high-frequency signal input from 01 has the antenna switch 102 on the 102r side and the mode switch 129.
Is connected to the contact 129b side, the reception frequency fR of the local station of 810 to 826 MHz is selected by the high-frequency bandpass filter 103b and input to the high-frequency amplifier 104b, where it is amplified, and further amplified by the high-frequency bandpass filter 105b. After increasing the selectivity, the converter 106
b, where it is mixed with the first local oscillation frequency fL1b of 680.9 to 696.9 MHz input from the first local oscillator 108b and converted into the first intermediate frequency fR1b of 129.1 MHz, and the first intermediate frequency fR1b. The selectivity is increased by the bandpass filter 109b and the first intermediate frequency amplifier 11
0b, and the oscillation frequency from the second local oscillator 112a having the second local oscillation frequency fL2a of 129.55 MHz is mixed with the converter 111b to 450 kHz.
To the second intermediate frequency fR2b, the selectivity of which is increased by the second intermediate frequency bandpass filter 115b and demodulated by the demodulator 116b to obtain a reception output.

During transmission, the second local oscillator 112b outputs the second
The transmission intermediate frequency fT1 obtained by digitally modulating the 259.1 MHz output of the local oscillation frequency fL2b with the modulation signals I and Q by the modulator 119 is amplified by the transmission intermediate frequency amplifier 120, and the selectivity is increased by the transmission intermediate frequency bandpass filter 121. After that, the contact 130 of the mode changeover switch 130
680.9 to 69 from the first local oscillator 108b from b
Input the first local oscillation frequency fL1b of 6.9 MHz to the converter 122, where 940 to 956 MHz
Is converted into a high frequency signal having a transmission frequency fTb of its own station, and the selectivity is increased from the contact point 132b of the mode switch 132 by the high frequency band pass filter 123b.
24b, after being amplified by the high frequency power amplifier 125b and having increased selectivity by the high frequency band pass filter 126b,
The signal is transmitted from the antenna 101 through the contact 131b of the mode changeover switch 131 and the contact 102t of the antenna changeover switch 102. Reception and transmission are performed by antenna changeover switch 102 and mode changeover switch 1
Simultaneous transmission / reception can be performed by switching 33 at a cycle shorter than that of the voice signal. For example, 1
20/3 msec when the frame is 20 msec
Is transmitted, 1 msec space is received, then 20/3 msec is received, and the rest is waited.

As described above, in the conventional example, in the TDMA radio apparatus, the FDD and TDD transmission units are integrated, the FDD and TDD reception units are integrated, and the first local oscillation circuit is divided into two. One is used for TDD system transmission and reception, the other one is used for FDD system transmission and reception, and the second local oscillator circuit has a second local oscillator of 259.1 MHz for the TDD system. 11
2b is used for transmission and reception. For the FDD system, the second local oscillator 112b is used for transmission and 12 Fx for reception.
A second local oscillator 112a of 9.55 MHz is used, and two second local oscillators 112a and 112b are required.

[0010]

However, in the conventional multi-frequency band voltage controlled oscillator as described above, a voltage controlled oscillator must be provided for each target frequency band, and time division multiplexing FDD / TDD dual is used. Even in mode radios, the transmission / reception frequency differs depending on the mode, so it is necessary to change the frequency bands of the first and second local oscillation frequencies in accordance with the mode. Therefore, multiple frequency band voltage controlled oscillators, time division multiplexing FDD In both / TDD dual mode radios, a voltage-controlled oscillator must be provided for each target frequency band, which causes an increase in circuit scale and space and is costly.

The present invention has been made to solve the above-mentioned conventional problems, and a voltage control oscillator having a plurality of frequency bands which can be used for a plurality of frequency bands with a simple circuit by switching the oscillation element of the voltage control oscillator, and the same. It is an object of the present invention to provide a time division multiplexing FDD / TDD dual mode radio device using.

[0012]

In order to achieve the above object, the first structure of the multi-frequency band voltage controlled oscillator according to the present invention is such that a variable voltage is applied to one end to equivalently change its capacitance. A variable capacitance element whose end is AC grounded, a distributed constant line whose DC end is insulated from the variable capacitance element, and one end of which is AC connected, a second end of the distributed constant line and an AC ground potential. And a switch connected between.

Similarly, in the second configuration, a variable capacitance element in which a variable first voltage is applied to one end to equivalently vary its capacitance and the other end is grounded in an alternating current is A distributed constant line insulated from DC and connected to one end in AC, a switching element connected between the other end of the distributed constant line and an AC ground potential, and applied from one end of the distributed constant line And a second voltage that turns on the switching element through the distributed constant line.

In the above structure, a capacitor can be connected in parallel to the distributed constant line in an alternating current manner.

As a modification of the first and second configurations,
The distributed constant line may be divided into at least two pieces, and may have a switch or a switching element connected between them, and the other end of the distributed constant line of this configuration may be AC-grounded.

As a modification of the first and second configurations, the distributed constant line has at least one switch or switching element having the other end grounded in an alternating current in the middle thereof, and at least two distributed constant lines. It is possible to connect at least one switch or switching element which has a switch or a switching element connected between them and whose other end is AC grounded to the middle of the portion of the distributed constant line.

Next, in order to achieve the above object, a time-division multiplex FD using the multiple frequency band voltage controlled oscillator of the present invention.
The D / TDD dual mode radio device includes a first local oscillating means, an output obtained by selectively amplifying a high frequency signal of a receiving frequency input from a receiving input terminal for the FDD system, and an output of the first local oscillating means. First output signal conversion means for FDD system that outputs the frequency difference as a first intermediate frequency for FDD system, second local oscillation means, and output of the first reception signal conversion means for FDD system are selected. Second amplified signal output means for outputting the sum or difference frequency of the amplified output and the output of the second local oscillating means, and the received frequency input from the receive input terminal for the TDD method. First reception signal conversion means for the TDD system, which outputs the frequency difference between the output obtained by selectively amplifying the high frequency signal of the above and the output of the first local oscillation means as the first intermediate frequency for the TDD system, and the TD. Second received signal conversion means of the FDD system, which outputs a frequency of the sum or difference between the output obtained by selectively amplifying the output of the first received signal conversion means of the system and the output of the second local oscillation means, A modulator for modulating the output of the second local oscillating means, the sum of the output obtained by selectively amplifying the output of the modulator and the output of the first local oscillating means, and the reception frequency for the FDD system. FDD different from
And a TDD transmission frequency which is the sum of the output of the first local oscillation means and the output obtained by selectively amplifying the output of the modulator, and which is the same as the reception frequency for the TDD system. And a transmission / reception / mode control means for switching the respective oscillation frequency bands of the first and second local oscillators in accordance with a use mode and for transmission / reception. Two
Any one of the local oscillating means is characterized by using the plural frequency band voltage controlled oscillator having the above configuration.

[0018]

In the multi-frequency band voltage controlled oscillator according to the present invention, the effective length of the distributed constant line is changed by turning on / off the switch or turning on / off the switching element by the second voltage in the above structure. Change the resonance frequency band by changing the resonance mode by deciding whether or not to ground the other end of the distributed constant line, and then changing the voltage applied to the variable capacitance element to change the oscillation frequency. Fine adjustment is performed to act to obtain a desired oscillation frequency in a plurality of frequency bands.

The time division multiplex FDD / TDD dual mode radio using the multiple frequency band voltage controlled oscillator of the present invention has a transmitter / receiver usage mode and transmission
The transmission / reception / mode control means switches and controls the frequency band of at least one of the first and second local oscillating means using a plurality of frequency band voltage controlled oscillators according to each combination of reception, and each frequency conversion means controls each frequency band. By controlling the frequency relationship during reception and transmission so as to match the frequency that can be handled by the circuit, transmission and reception can be performed with a small number of oscillation means.

[0020]

【Example】

(First Embodiment) A multi-frequency band voltage controlled oscillator according to an embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a circuit diagram of essential parts of a multiple frequency band voltage controlled oscillator according to a first embodiment of the present invention. In FIG. 1, the frequency varying voltage VT applied to the frequency varying voltage terminal 1 is bypassed by the capacitors 2 and 3 and applied to the cathode of the variable capacitance diode 5 via the coil 4. The cathode of the variable capacitance diode 5 is connected to the distributed constant line 7 and the resonance capacitor 9 via the capacitor 6, and the anode thereof is grounded. The other end of the distributed constant line 7 is grounded via a band change switch 15. Thus, the variable capacitance diode 5, the distributed constant line 7, and the resonance frequency adjusting capacitor 9 constitute a resonance circuit. The other ends of the capacitors 2, 3 and 9 are grounded.

The connection point between the distributed constant line 7 and the resonance capacitor 9 is further connected to the collector of the oscillating transistor 20 via the capacitor 14, and the collector receives the power supply voltage from the power supply terminal 16 via the choke coil 21. Is being supplied. The base of the transistor 20 is supplied with the power supply voltage divided from the power supply terminal 17 by the resistors 18 and 19, and this connection point is grounded via the capacitor 23 for cutting the direct current. Furthermore, a capacitor 22 is provided between the collector and the base of the oscillating transistor 20.
However, the capacitor 24 is connected between the collector and the emitter, and the emitter of the transistor 20 is grounded after the capacitor 25 and the choke coil 26 are connected in parallel. Then, from this resonance circuit, the capacitor 27 is connected to the power source 29 via the coil 30 and is connected to the base of the buffer transistor 28 whose collector is connected,
The output terminal 31 is connected to the collector.

With the above-mentioned configuration and the operation thereof will be described below, first, the band changeover switch 15 in the figure is short-circuited in order to determine the oscillation frequency band. Then the resonant circuit including the distributed constant line 7 for one end of the distributed constant line 7 is grounded, lambda ₁ = 4L i.e. L = λ _1/4 becomes the wavelength lambda ₁
It resonates in a frequency band based on (1/4 wavelength mode) and oscillates in an oscillation circuit including the transistor 20. Then, as in the previous case, by applying the frequency varying voltage VT given to the frequency varying voltage terminal 1 to the variable capacitance diode 5, the equivalent capacitance of the variable capacitance diode 5 is changed and the oscillation frequency is finely adjusted. Transistor 20
The oscillation output oscillated by the oscillation circuit including
The signal is output from the buffer circuit of 8 through the output terminal 31.

Next, in order to change the oscillation frequency band, the band changing switch 15 shown in the figure is opened. Then, since the resonance circuit including the distributed constant line 7 has one end of the distributed constant line 7 open, the length of the distributed constant line 7 is set to L.
To the lambda ₂ = a 2L i.e. L = λ _2/2 becomes the wavelength lambda ₂ resonates at a frequency band of the base (hereinafter half wavelength mode), which oscillates at an oscillation circuit including the transistor 20. Then, the frequency varying voltage VT given to the frequency varying voltage terminal 1 is applied to the cathode of the variable capacitance diode 5 to change the equivalent capacitance of the variable capacitance diode 5 to finely adjust the oscillation frequency.

At this time, the respective resonance frequencies f ₁ and f ₂
Is f ₁ = k / λ ₁ , f ₂ = k / λ ₂ (where k is a constant determined by the distributed constant line). Therefore, f ₁ = k / 4L, f ₂ = k / 2L and the band switching switch 15 is opened. That is, when the distributed constant line 7 is opened at the tip and resonated at 1/2 wavelength, the resonance occurs in the frequency range in which the frequency is twice as high.

(Second Embodiment) FIG. 2 is a circuit diagram of a second embodiment of the present invention, and FIG. 3 is a circuit diagram of a main part of a resonance circuit when one end of the distributed constant line is also open, FIG. 4 is a circuit diagram of the main part of the resonance circuit when one end of the distributed constant line is grounded. Hereinafter, parts having the same functions as those in FIG. 1 of the first embodiment are designated by the same reference numerals, and detailed description thereof will be omitted. The point that the frequency varying voltage VT is applied as the first voltage to the frequency varying voltage terminal 1 is shown in FIG. 1 of the first embodiment.
1, but the difference from FIG. 1 is that the anode of a switching diode 8 which is a switching element is connected instead of the band switching switch 15 at the other end of the distributed constant line 7, and the cathode thereof is grounded. Further, a coil 11 is connected to a connection point between the resonance frequency adjusting capacitor 9 and the distributed constant line 7, and the other end of the coil 11 is a frequency band switching power supply terminal 10 to which a frequency band switching voltage VS which is a second voltage is applied. From which point capacitors 12 and 13 are grounded. The capacitors 12 and 13 are provided with a plurality of capacitors having the same characteristics as those of the capacitors 2 and 3 to completely bypass the high frequency component so as to prevent the high frequency component from leaking to the outside and prevent the noise component from being mixed from the outside.

With the above-mentioned structure and the operation thereof will be described below, first, in order to determine the oscillation frequency band, a ground potential or a negative potential is applied as the frequency band switching voltage VS to the frequency band switching power supply terminal 10 in the figure. Then, since the switching diode 8 does not conduct, the other end of the distributed constant line 7 is equivalently open. Then, since one end of the distributed constant line 7 is open in the resonance circuit including the distributed constant line 7, the resonant circuit resonates in a high frequency band similarly to the first embodiment based on the ½ wavelength mode, and the oscillation including the transistor 20 occurs. It oscillates in the circuit. Then, the frequency varying voltage VT given to the frequency varying voltage terminal 1 is applied to the variable capacitance diode 5 which is a variable capacitance element to change the equivalent capacitance of the variable capacitance diode 5 to finely adjust the oscillation frequency. . The oscillation output oscillated by the oscillation circuit including the transistor 20 is output from the buffer circuit including the transistor 28 via the output terminal 31.

Next, in order to lower the oscillation frequency band, a frequency band switching voltage VS for turning on the switching diode 8 is applied to the frequency band switching power supply terminal 10. Then, the other end of the distributed constant line 7 is grounded by the switching diode 8 which is turned on by the frequency band switching voltage VS passing through the distributed constant line 7. Since one end of the distributed constant line 7 is grounded in the resonant circuit including the distributed constant line 7, the resonant circuit resonates in a low frequency band of about ½ based on the ¼ wavelength mode, and the transistor 2
It oscillates in the oscillation circuit including 0. Then, as in the previous case, the frequency varying voltage VT applied to the frequency varying voltage terminal 1
Is applied to the variable capacitance diode 5, the equivalent capacitance of the variable capacitance diode 5 is changed and the oscillation frequency is finely adjusted. In this embodiment, the variable capacitance diode 5
If the resonance frequency can be determined by the distributed constant line 7 and the distributed constant line 7, the capacitor 9 is not always necessary.

The switching diode 8 can be replaced with another switching element having an equivalent function, for example, a field effect transistor (hereinafter referred to as FET).
In this case, the frequency band switching control voltage is applied to the gate terminal without passing through the distributed constant line.

(Third Embodiment) FIG. 5 is an explanatory view showing a combination of distributed constant lines according to a third embodiment of the present invention. In FIG. 5 (a), the distributed constant lines have different lengths 7a. And 7b, a switch 15a is provided in the middle, and the other end is grounded AC-wise. When the switch 15a is turned on, as shown in FIG. 5 (b), one end is grounded to become a distributed constant line which resonates in the quarter wavelength mode with a length of L ₁ + L ₂ , and when the switch 15a is turned off, the state shown in FIG. As shown in (c), the length is L ₁ and the distributed constant line resonates in the 1/2 wavelength mode. By connecting the circuit of FIG. 5 (a) instead of the distributed constant line 7 in the circuit of FIG. By selecting the lengths of ₁ and L ₂ to appropriate values, the frequency band is not limited to 1: 2, and the flexibility of the resonant frequency band that can be switched is increased.

In FIG. 5 (a), there is 1 between two distributed constant lines.
Although three switches are connected, three or more frequency bands can be selected by increasing the number of divisions of the distributed constant line and the number of switches. In this case, the other end of the distributed constant line does not necessarily have to be grounded.

If the circuit of FIG. 5A is used as the distributed constant line of the circuit of FIG. 2 of the second embodiment and the diode 8 is provided instead of the switch 15a, the above operation is realized by the circuit of FIG. can do. In this case, since the diode can select only two frequency bands, three or more frequency bands can be selected by using a switching element such as FET.

(Fourth Embodiment) FIG. 6 is an explanatory view showing a combination of distributed constant lines in a fourth embodiment of the present invention. In FIG. 6A, the length is L ₁ + L ₂ , and it is configured such that the portion from the one end to L ₁ can be grounded by the switch 15b. Then, when the switch 15b is turned on, a distributed constant line having a length L ₁ and resonating in the quarter wavelength mode is obtained as shown in FIG. 6B, and when the switch 15a is turned off, as shown in FIG. 6C. It becomes a distributed constant line having a length of L ₁ + L ₂ and resonating in the 1/2 wavelength mode. By connecting the circuit of FIG. 6A instead of the distributed constant line 7 in the circuit of FIG. 1, L ₁ and L ₂ are connected. By appropriately selecting the length, the frequency band is not limited to 1: 2, and the degree of freedom of the resonant frequency band that can be switched is increased.

If the circuit of FIG. 6A is used for the distributed constant line of the circuit of FIG. 2 of the second embodiment and the diode 8 is provided instead of the switch 15a, the above operation is realized by the circuit of FIG. can do.

In FIG. 6 (a), one switch is connected in the middle of one distributed constant line, but three or more frequency bands can be selected by increasing the number of switches and turning them on alternately. You can In this case, the combination of grounding the other end of the distributed constant line is not always necessary. In this case, the diode can select only two frequency bands, so if a switching element such as a FET transistor is used,
The above frequency bands can be selected.

(Fifth Embodiment) FIG. 7 is an explanatory view showing a combination of distributed constant lines in a fifth embodiment of the present invention. In FIG. 7, the distributed constant line 7 of the circuit of FIG.
The switch 15c can be grounded in the middle of a or 7b. It is possible to switch to three frequency bands by turning off both the switches 15a and 15c or turning on either of the switches 15a and 15c. The frequency band that can be switched can be increased by further increasing the number of switches. This is shown in Figure 6.
Even if the number of switches in the circuit (a) is increased, the same operation can be performed.

In the fifth embodiment, the switch 15
Instead of a or 15c, a switching element such as an FET can be used, and by controlling the gate potentials of these transistors, connection / disconnection between distributed constant lines and ground / open can be freely switched.

As described above, according to the first and second embodiments, the resonance mode of the distributed constant line is reduced to 1/2 by turning on / off the switch or the switching diode provided at the other end of the distributed constant line. By switching from the wavelength to the quarter wavelength, the dual frequency band voltage controlled oscillator can be realized with a simple configuration.

According to the third or fourth embodiment, the switch or switching diode provided between the at least two distributed constant lines is turned on or off, or one distributed constant is provided. The length of the distributed constant line can be changed with a simple configuration by turning on / off the switch or switching diode provided so that it can be grounded from the middle of the line, and the resonance mode can be switched from 1/2 wavelength to 1/4 wavelength. It is possible to realize a multi-frequency band voltage controlled oscillator that is capable of setting frequency bands with a high degree of freedom.

Furthermore, according to the fifth embodiment, the third and fourth embodiments are combined, and plural frequency band voltage control capable of switching three or more frequency bands by turning on and off two or more switches. An oscillator can be realized.

The configurations of the resonance circuit periphery, the oscillation circuit and its peripheral circuit shown in the figure are not limited to those shown in the figure, and may be modified or used in combination within the scope of achieving the object of the present invention. It doesn't matter. Further, although the capacitor, the variable capacitance diode, and the switching diode are described as being directly grounded, of course, they may be AC-grounded.

Further, the variable capacitance diode and the switching diode may be replaced with other elements having an equivalent function. For example, the switching diode 8 may be replaced with a field effect transistor (FET) or the like. In this case, the frequency band switching control voltage is applied without passing through the distributed constant line.

(Sixth Embodiment) Next, FIG. 8 is a block diagram of a time division multiplex FDD / TDD dual mode radio using a multiple frequency band voltage controlled oscillator according to a sixth embodiment of the present invention. It demonstrates using. Figure 1 of the conventional example
The main difference from 0 is that in FIG. 10, two first local oscillator circuits are provided for the FDD system and two for the TDD system, and two second local oscillator circuits are provided for the FDD system and TDD system. This is a point in which each of them is made into one by using the two frequency band voltage controlled oscillators. With respect to the constituent elements of the respective parts and their combined connection, the parts having the same functions as those in the conventional example of FIG. 10 are designated by the same reference numerals, and detailed description thereof will be omitted. In FIG. 8, the multiple frequency band voltage controlled oscillator 108 as described in the first to fifth embodiments is used for the first local oscillator, and the multiple frequency band as described in the first to fifth embodiments is also used for the second local oscillator. The voltage-controlled oscillator 112 (both of which have two frequency bands in the sixth embodiment) is used.

First, in the TDD mode, the mode changeover switches 129, 131 and 132 are set to 129a,
Switch to the side of 131a and 132a. When receiving, the high frequency signal input from the antenna 101 has the antenna changeover switch 102 connected to the 102r side, and therefore passes through the mode changeover switches 129 and 129a and is passed through the high frequency band pass filter 103a by 1895.15.
The reception frequency fRa of its own station of ˜191.95 MHz is selected and input to the high frequency amplifier 104a, amplified here, and further increased in selectivity by the high frequency band pass filter 105a, and then input to the converter 106a. 1 local oscillator 1 which is a two frequency band voltage controlled oscillator
08 is mixed with a first local oscillation frequency fL1a of 1646.85-1669.65 MHz, which is a frequency band selected for TDD reception by a transmission / reception / mode controller (control means) not shown, and a first frequency of 248.3 MHz is mixed.
The frequency 259 converted to the intermediate frequency fR1a, increased in selectivity by the first intermediate frequency bandpass filter 109a, amplified by the first intermediate frequency amplifier 110a, and also selected for TDD reception by the transmission / reception / mode controller (not shown). The second local oscillation frequency fL2b, which is a two-frequency band voltage controlled oscillator that oscillates 1 MHz,
Oscillation frequency from local oscillator 112 and converter 111
It is mixed in a and converted into the second intermediate frequency fR2 of 10.8 MHz, the selectivity is increased by the second intermediate frequency bandpass filter 115a, and demodulated by the demodulator 116a to obtain a reception output.

At the time of TDD transmission, the transmission intermediate frequency fT1 obtained by digitally modulating the 259.1 MHz output of the second local oscillation frequency fL2b of the second local oscillator 112 with the modulation signals I and Q by the modulator 119 is amplified by the transmission intermediate frequency amplifier 120. After the selectivity is increased by the transmission intermediate frequency bandpass filter 121, the first local oscillator 1 is also used for TDD transmission by a transmission / reception / mode controller (not shown).
08 to 1636.0 in a frequency range different from that at the time of reception.
5 to 1658.85MHz 1st local oscillation frequency fL1a
Input to the converter 122,
Transmission frequency f of own station of 5.15 to 1917.95 MHz
The signal is converted into a high frequency signal of T, the selectivity is increased by the high frequency band pass filter 123a from the contact 132a of the mode switch 132, and is amplified by the high frequency amplifier 124a and the high frequency power amplifier 125a.
After the selectivity is increased by 26a, the contact 131a of the mode changeover switch 131 and the antenna changeover switch 1
The signal is transmitted from the antenna 101 through the contact 102t of No. 02. The antenna changeover switch 102 is used for reception and transmission.
Is switched at high speed as in the conventional example. At the time of reception, the operation of each device (amplifier, converter, modulator, etc.) of the transmission circuit is turned off by a transmission / reception / mode controller (not shown), and at the same time, each device of the reception circuit is turned off at the time of transmission.

Next, the FDD mode will be described. Set the mode changeover switches 129, 131 and 132 to
It is switched to the 129b, 131b and 132b side. The high-frequency signal input from the antenna 101 at the time of reception is selected by the high-frequency bandpass filter 103b to select the reception frequency fR of its own station by the high-frequency band-pass filter 103b because the antenna change-over switch 102 is connected to the 102r side and the mode change-over switch 129 is connected to the contact 129b side. And input it to the high frequency amplifier 104b, where it is amplified,
After the selectivity is further increased by the high frequency band pass filter 105b, it is input to the converter 106b, where it is transmitted / received.
680.9 to 6 input from the first local oscillator 108 whose band is set for FDD reception by the mode controller
It is mixed with the first local oscillation frequency fL1b of 96.9 MHz and converted into the first intermediate frequency fR1b of 129.1 MHz, and the selectivity is increased by the first intermediate frequency bandpass filter 109b and amplified by the first intermediate frequency amplifier 110b. Is
Further, the local oscillation frequency from the second local oscillator 112 having the second local oscillation frequency fL2a of 129.55 MHz which is band-set for FDD reception by the transmission / reception / mode controller is mixed by the converter 111a to the second intermediate frequency fR2b of 450 kHz. The converted signal is converted, the selectivity is increased by the second intermediate frequency band pass filter 115b, and demodulated by the demodulator 116b to obtain a reception output.

At the time of transmission, the second 259.1 MHz signal set for FDD transmission by the transmission / reception / mode controller
The transmission intermediate frequency fT1 obtained by digitally modulating the oscillation frequency output of the second local oscillator 112 having the local oscillation frequency fL2b with the modulation signals I and Q by the modulator 119 is amplified by the transmission intermediate frequency amplifier 120, and is transmitted by the transmission intermediate frequency bandpass filter 121. After increasing the selectivity, the same is input to the converter 122 which receives the first local oscillation frequency fL1b of 680.9 to 696.9 MHz from the first local oscillator 108 also set for FDD transmission by the transmission / reception / mode controller, Here, the transmission frequency f of the own station of 940 to 956 MHz
It is converted into a high frequency signal of Tb, the selectivity is increased from the contact 132b of the mode switch 132 by the high frequency band pass filter 123b, amplified by the high frequency amplifier 124b and the high frequency power amplifier 125b, and the high frequency band pass filter 1 is obtained.
After the selectivity is increased by 26b, the contact 131b of the mode changeover switch 131 and the antenna changeover switch 1
The signal is transmitted from the antenna 101 through the contact 102t of No. 02. The antenna changeover switch 102 is used for reception and transmission.
Also, simultaneous transmission / reception can be performed by switching the mode changeover switch 33 at a cycle shorter than that of the voice signal.

As described above, in this embodiment, TDMA is performed.
System wireless device, the FDD system and the TDD system transmitter are integrated, and the FDD system and the TDD system receiver are integrated, and the first local oscillation circuit and the second local oscillation circuit are two frequency band voltage controlled oscillators. Is provided and controlled by a transmission / reception / mode controller (not shown) according to the mode and the transmission / reception state, two carrier wave oscillators can be omitted and the number of oscillators can be reduced as compared with the conventional dual mode radio. it can.

In this embodiment, the plural frequency band voltage controlled oscillators of the first to fifth embodiments are used for both the first and second local oscillator circuits, but it is not always necessary to use them for both. Even if it is used for either one of the second local oscillation circuits, one oscillator can be omitted and the number of oscillators can be reduced by one compared with the conventional example.

In this embodiment, both the first local oscillation circuit and the second local oscillation circuit have been described with the two frequency band voltage controlled oscillators. However, when the used frequency band is large, a plurality of frequency band voltage controlled oscillators with three or more frequency bands are used. be able to.

[0050]

As described above, the multiple frequency band voltage controlled oscillator of the present invention is a variable capacitance element in which a variable voltage is applied to one end to equivalently change its capacitance and the other end is grounded in an alternating current. And a distributed constant line that is DC-isolated from the variable capacitance element and has one end connected to the AC, and a switch that is connected between the other end of the distributed constant line and an AC ground potential. ing.

In the second configuration, a switching element is provided instead of the switch of the first configuration, and a second voltage applied from one end of the distributed constant line to turn on the switching element through the distributed constant line. To give.

In the first and second configurations, the distributed constant line is divided into a plurality of parts, and a switch or a switching element is connected therebetween, or the other end of the distributed constant line is grounded in an alternating current. Yes, or by connecting at least one switch or switching element with the other end grounded AC in the middle of the distributed constant line, or by combining these, a single voltage controlled oscillator generates frequencies in multiple bands. Therefore, the circuit scale and the space can be reduced, and the cost can be reduced.

A time division multiplex FDD / TDD dual mode radio using the multiple frequency band voltage controlled oscillator of the present invention uses the multiple frequency band voltage controlled oscillator of the present invention as the first and second local oscillators. The transmission / reception / mode control means controls the switching of the frequency bands of the first and second local oscillation means according to the combination of the usage mode of the transceiver and the transmission / reception, and the frequency at the time of reception and transmission of each portion in each frequency conversion means. By controlling the relationship so as to match the frequency that can be handled by the circuit, transmission and reception can be performed with a small number of oscillating means, the circuit scale can be reduced, the space can be reduced, and the cost can be reduced.

[Brief description of drawings]

FIG. 1 is a circuit diagram of a main part of a multiple frequency band voltage controlled oscillator according to a first embodiment of the present invention.

FIG. 2 is a circuit diagram of a main part of a multiple frequency band voltage controlled oscillator according to the second embodiment.

FIG. 3 is a circuit diagram of a main part of a resonance circuit for explaining the operation thereof.

FIG. 4 is a circuit diagram of a main part of a resonance circuit for explaining another operation state.

FIG. 5 is an explanatory view showing a combination of distributed constant lines in the third embodiment.

FIG. 6 is an explanatory view showing a combination of distributed constant lines in the fourth embodiment.

FIG. 7 is an explanatory view showing a combination of distributed constant lines according to the fifth embodiment.

FIG. 8 is a block diagram of a time division multiplexing FDD / TDD dual mode radio using a multiple frequency band voltage controlled oscillator of the present invention.

FIG. 9 is a block diagram of a conventional multi-frequency band voltage controlled oscillator.

FIG. 10 is a block diagram of a time division multiplex FDD / TDD dual mode radio using the same frequency band voltage controlled oscillator.

[Explanation of symbols]

 1 frequency variable voltage terminal 5 variable capacitance diode 5 6 capacitor 7 distributed constant line 8 switching diode 9 resonance frequency adjusting capacitor 10 frequency band switching power supply terminal 15 switch VT frequency variable voltage VS frequency band switching voltage 106, 111, 122 converter 108 first local oscillator 112 second local oscillator 119 modulator

Front page continuation (72) Inventor Yoichi Morinaga 1006 Kadoma, Kadoma City, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. Toru Yamada 1006 Kadoma, Kadoma-shi, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (9)

[Claims] 1. A plurality of frequency resonance means in which a switch is connected between one end of a distributed constant line and an AC ground potential, and a variable voltage is applied to one end to equivalently change its capacitance, and the other end is AC. Frequency adjusting means composed of a variable capacitance element grounded electrically, feedback amplification means having a negative resistance characteristic composed of a transistor, a coil, a capacitor and a resistor,
A multi-frequency band voltage controlled oscillator, wherein the frequency adjusting means and the feedback amplifying means are connected in an alternating manner to the other end of the distributed constant line of the multi-frequency resonance means. 2. A plurality of frequencies including a switching element connected to one end of the distributed constant line between an AC ground potential and a first voltage for turning on / off the switching element from the other end or the middle of the distributed constant line. From the resonance means, the frequency adjusting means composed of the variable capacitance element in which the variable second voltage is applied to one end and the capacitance is equivalently changed and the other end is grounded in alternating current, the transistor, the coil, the capacitor, and the resistor. And a feedback amplification means having a negative resistance characteristic, wherein the frequency adjustment means and the feedback amplification means are AC-connected to the other end of the distributed constant line of the multiple frequency resonance means. Multiple frequency band voltage controlled oscillator. 3. The multiple frequency band voltage controlled oscillator according to claim 1, wherein a capacitor is connected in parallel to the distributed constant line in an alternating current manner. 4. The multi-frequency resonance means resonates in a short-circuited quarter-wavelength resonance mode when the switch is turned on, and in a tip-opened half-wavelength resonance mode when the switch is turned off. The multi-frequency band voltage controlled oscillator according to claim 3. 5. The multi-frequency band voltage controlled oscillator according to claim 1, wherein the distributed constant line is divided into at least two pieces and has a switch or a switching element connected between them. 6. The distributed constant line according to claim 1, wherein the distributed constant line is divided into at least two, and a switch or a switching element is connected between them, and the other end of the distributed constant line is AC-grounded. 7. A multi-frequency band voltage controlled oscillator according to claim 1. 7. The multi-frequency band voltage controlled oscillator according to claim 1, wherein at least one switch or switching element having the other end grounded in an alternating current is connected to the middle of the distributed constant line. . 8. A distributed constant line is divided into at least two parts, and has a switch or a switching element connected between them, and at least one part of which is connected to the other end in the middle of the part of the distributed constant line in an AC manner. 5. The multi-frequency band voltage controlled oscillator according to claim 1, wherein the switch or the switching element is connected. 9. A frequency difference between the output of the first local oscillating means and the output of the first local oscillating means and the output obtained by selectively amplifying the high frequency signal of the receiving frequency input from the receiving input terminal for the FDD system. The output of the first received signal conversion means for the FDD system, which outputs as the first intermediate frequency for the system, the second local oscillation means, and the output of the first received signal conversion means of the FDD system, is selectively amplified. The second received signal conversion means for the FDD system, which outputs the frequency of the sum or difference between the output and the output of the second local oscillation means, and the high frequency signal of the received frequency input from the reception input terminal for the TDD system. TD for outputting the frequency difference between the selectively amplified output and the output of the first local oscillation means as a first intermediate frequency for the TDD system
A first reception signal converting means for the D system, and a frequency of a sum or a difference between an output obtained by selectively amplifying an output of the first reception signal converting means of the TDD system and an output of the second local oscillating means. FDD second received signal converting means, a modulator for modulating the output of the second local oscillating means, an output obtained by selectively amplifying the output of the modulator, and the first local oscillation. A sum of the output of the FDD system and an FDD transmission frequency different from the reception frequency for the FDD system, and an output obtained by selectively amplifying the output of the modulator and an output of the first local oscillation means. And a transmission signal conversion means for generating the same TDD transmission frequency as the reception frequency for the TDD system, and the oscillation frequency bands of the first and second local oscillators for the use mode and the transmission frequency band, respectively.
9. A transmission / reception / mode control means for switching according to reception, wherein at least one of the first and second local oscillation means is a multi-frequency band voltage controlled oscillator according to any one of claims 1 to 8. A time division multiplex FDD / TDD dual mode radio characterized by being used.