JP2004356801A - Multi-band oscillator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a multi-band oscillator having a plurality of desired bands capable of covering the frequency band of a plurality of communication systems by connecting a single oscillator with wideband frequency dividers by two, and to obtain a multi-band oscillator in which reduction in cost and size of a multi-band transceiver is realized. <P>SOLUTION: The multi-band oscillator comprises a frequency synthesizer 1 corresponding to a communication system having a highest frequency band, n frequency dividers by two 2-1 to 2-n, n switches 3-1 to 3-n, an output terminal 4 connected with the n-th frequency divider by two 2-n, and a frequency control section 5 for controlling the frequency synthesizer 1 and the switches 3-1 to 3-n wherein the variable frequency range of the frequency synthesizer 1 is set at octave. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a multiband oscillator having a local oscillation circuit function capable of generating a signal in a wide frequency range by one oscillator including a divide-by-2 or variable divider and a variable multiplier over a wide band. .
[0002]
In recent years, various wireless communication systems such as mobile phones and wireless LANs have become widespread, and in the future, digital TVs, third-generation mobile phones (W-CDMA), and the like are expected to become more popular.
At present, this type of communication system is commercially available as separate terminals, but there is a portable terminal having a function capable of transmitting and receiving a plurality of systems with one terminal (that is, a function capable of supporting multiband and multimode). It is desired.
[0003]
An example of a conventional multiband oscillator applied to a transmission / reception analog unit is one having a voltage-controlled oscillator (VCO) for a desired frequency (n) (see, for example, Patent Document 1).
In the case of the conventional device described in Patent Document 1, a multiband antenna and a voltage controlled oscillator connected to the control unit, and a mixer, a demodulation unit, and a modulation unit related thereto are provided, and the control unit responds to a desired frequency band. Switching command is output, and the voltage controlled oscillator and multiband antenna are switched to support multiband and multimode.
[0004]
A general frequency synthesizer includes a reference oscillator, a variable multiplier, a phase comparison circuit, a variable frequency divider, and a voltage controlled oscillator. The variable frequency divider divides the output of the voltage controlled oscillator to the output frequency of the reference oscillator. Then, the divided signal and the output signal of the reference oscillator are compared by a phase comparison circuit, and the error component obtained by the phase comparison is negatively fed back to the voltage controlled oscillator for stabilization (for example, non-patent document) 1).
[0005]
[Patent Document 1]
JP 2000-269848 A [Non-Patent Document 1]
"Monolithic Microwave Integrated Circuit" (Co-authored by IEICE, Masayoshi Aikawa et al., P. 148)
[0006]
[Problems to be solved by the invention]
Since the conventional multi-band oscillator is configured as described above, it is necessary to prepare a number of voltage controlled oscillators corresponding to the number of communication systems in order to realize a terminal compatible with a large number of communication systems. There has been a problem of incurring cost and cost increase.
[0007]
The present invention has been made to solve the above-described problems. By connecting a wide-band divide-by-2 or variable divider and variable multiplier to an oscillator, the frequency band of a plurality of communication systems can be reduced. An object of the present invention is to realize a multiband oscillator having a plurality of desired bands that can be covered, and to obtain a multiband oscillator in which the cost and size of a multiband transceiver are reduced.
[0008]
[Means for Solving the Problems]
The multiband oscillator according to the present invention is a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems, and corresponds to a communication system having the highest frequency band among the plurality of communication systems. A frequency synthesizer, n two frequency dividers having different bandwidths and connected in parallel, n switches for switching the n two frequency dividers to connect to the frequency synthesizer, and n dichotomies It has an output terminal connected to the n-th divide-by-two frequency divider, a frequency synthesizer and a frequency control unit that controls the n switches, and the frequency variable range of the frequency synthesizer is set to octave. N dividers are selectively used by being switched by a switch.
[0009]
A multiband oscillator according to the present invention is a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems, a frequency synthesizer, a variable frequency divider connected to the frequency synthesizer, and A variable frequency multiplier, an output terminal connected to the variable frequency multiplier, a frequency synthesizer, a variable frequency divider, and a frequency control unit that controls the variable frequency multiplier, the frequency division number of the variable frequency divider and the variable frequency multiplier The multiplication number is set in the frequency band of the plurality of communication systems under the control of the frequency control unit, and the frequency channel in the desired communication system among the plurality of communication systems is set by the frequency synthesizer under the control of the frequency control unit. Is.
[0010]
Further, a multiband oscillator according to the present invention is a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems, a frequency synthesizer, a variable multiplier connected to the frequency synthesizer, A phase comparison circuit, a voltage controlled oscillator and a variable frequency divider provided in a frequency synthesizer, and a frequency controller for controlling the variable frequency multiplier and the variable frequency divider, and the frequency multiplier and variable frequency divider of the variable frequency multiplier The frequency division number is set to a frequency band of a plurality of communication systems under the control of the frequency control unit, and the voltage controlled oscillator inputs a high frequency signal based on the output signal of the phase comparison circuit to the variable frequency divider, The output signal of the frequency is fed back to the phase comparison circuit, and a frequency channel in a desired communication system among a plurality of communication systems is obtained. Are those set by the frequency synthesizer under the control of the frequency control unit.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1 FIG.
Hereinafter, the first embodiment of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a block diagram showing a first embodiment of the present invention, and shows a circuit constituted by a frequency synthesizer 1 and variable frequency dividers 2-1 to 2-n.
In FIG. 1, a frequency synthesizer 1 is connected to a first ½ divider 2-1, a second ½ divider 2-2,. .
[0012]
The n frequency dividers 2-1 to 2-n have n switches 3- for selectively switching the frequency dividers 2-1 to 2-n and connecting them to the frequency synthesizer 1, respectively. 1, 3-2,..., 3-n are inserted.
The output terminal of the final-stage 2-frequency divider 2-n is connected to the output terminal 4 of the multiband oscillator.
The frequency control unit 5 controls the frequency synthesizer 1 and the switches 3-1 to 3-n.
[0013]
Next, the operation according to the first embodiment of the present invention shown in FIG. 1 will be described.
First, the frequency control unit 5 controls the frequency synthesizer 1 so that the upper limit of the oscillation frequency of the frequency synthesizer 1 corresponds to the communication system having the highest frequency band among the plurality of communication systems, and the frequency synthesizer 1 has a variable frequency. Set the range to be octave.
Further, the frequency control unit 5 turns on all the switches 3-1 to 3-n and connects the frequency dividers 2-1 to 2-n to the frequency synthesizer 1.
At this time, the high frequency signal output from the frequency synthesizer 1 passes through the n number of frequency dividers 2-1 to 2-n and is output from the output terminal 4.
[0014]
For example, when the desired frequency band is 0.8 GHz to 5 GHz, the frequency control unit 5 controls the lower limit frequency of the frequency synthesizer 1 to 4 GHz and controls the upper limit frequency to 8 GHz.
Thus, when the first switch 3-1 is set to the B side, a frequency of 4 GHz to 8 GHz is obtained from the output terminal 4, the first switch 3-1 is set to the A side (divided by 2), and When the 2 switch 3-2 is set to the B side, a frequency of 2 GHz to 4 GHz is obtained from the output terminal 4.
[0015]
Similarly, by setting the first and second switches 3-1 and 3-2 to the A side (divide by 4) and the third switch 3-3 to the B side, the output terminal 4 can set 1 GHz to 2 GHz. The frequency is obtained, and the output terminal 4 is set by setting the first to third switches 3-1 to 3-3 to the A side (divide by 8) and the fourth switch 3-4 to the B side. From 0.5 GHz to 1 GHz can be obtained.
[0016]
That is, by setting the m-th (m ≦ n) switches 3-1 to 3-m to the A side and the m + 1-th switch 3-m + 1 to the B side, the desired frequency is 2 ^m. As a result of dividing by ⁻¹ , the frequency after (m−1) frequency division can be obtained.
As described above, a single multiband oscillator including the frequency dividers 2-1 to 2-n over a wide band can transmit and receive a plurality of communication systems and a plurality of frequency bands to generate signals in a wide frequency range. Therefore, it is possible to reduce the size and cost of the multiband transceiver.
[0017]
Embodiment 2. FIG.
In the first embodiment, n frequency dividers 2-1 to 2-n are selectively connected to frequency synthesizer 1 through n switches 3-1 to 3-n. The variable frequency divider 6 and the variable multiplier 7 may be connected as shown in FIG.
FIG. 2 is a block diagram showing the first embodiment of the present invention. The same components as those described above (see FIG. 1) are denoted by the same reference numerals, or “A” after the reference numerals. Detailed description is omitted.
[0018]
In FIG. 2, a series circuit including a variable frequency divider 6 and a variable multiplier 7 is connected to the frequency synthesizer 1A.
The variable frequency divider 6 and the variable multiplier 7 are controlled by the frequency control unit 5A together with the frequency synthesizer 1A.
The frequency division number N of the variable frequency divider 6 and the frequency multiplication number M of the variable frequency multiplier 7 are variably set in frequency bands of a plurality of communication systems under the control of the frequency control unit 5A.
Further, a frequency channel in a desired communication system among the plurality of communication systems is set by the frequency synthesizer 1A under the control of the frequency control unit 5A.
Similarly to the above, the upper limit of the oscillation frequency of the frequency synthesizer 1A is controlled so as to correspond to the communication system having the highest frequency band among the plurality of communication systems.
[0019]
Next, the operation according to the second embodiment of the present invention shown in FIG. 2 will be described.
First, the frequency control unit 5A sets the oscillation frequency, the frequency division number N, and the multiplication number M of the frequency synthesizer 1A according to the frequency band of the desired communication system.
The high frequency signal output from the frequency synthesizer 1 </ b> A is output from the output terminal 4 via the variable frequency divider 6 and the variable multiplier 7.
[0020]
At this time, for example, in the case of the direct conversion method, when the frequency control unit 5A controls the oscillation frequency band of the frequency synthesizer 1A from 5 GHz to 6 GHz, the frequency division number N and the multiplication number M are set to “1”, respectively. Then, the output frequency band can be made compatible with 5 GHz band W-LAN (IEEE802.11a).
[0021]
Further, when the frequency division number N is set to “5” and the multiplication number M is set to “2”, the output frequency band is 2 GHz to 2.4 GHz, which corresponds to a 2 GHz band W-CDMA terminal.
Further, when the frequency division number N is set to “12” and the multiplication number M is set to “5”, the output frequency band is 2.08 GHz to 2.5 GHz, and the 2.4 GHz band W-LAN (IEEE802.11b). It comes to correspond.
[0022]
Channel setting in each communication system is performed by setting the frequency synthesizer 1A to a desired frequency under the control of the frequency controller 5A.
For example, in the case of W-CDMA, the channel of the communication system is set from 2.1125 GHz at intervals of 5 MHz.
Therefore, by changing the frequency of the frequency synthesizer 1A from 5.28125 GHz in 12.5 MHz steps, it is possible to correspond to the frequency of W-CDMA.
In this way, by performing transmission / reception of a plurality of communication systems and a plurality of frequency bands from one multiband oscillator, it is possible to realize a reduction in size and cost of the multiband transmitter / receiver.
[0023]
Embodiment 3 FIG.
In the second embodiment, the variable frequency divider 6 and the variable multiplier 7 are connected to the frequency synthesizer 1A. However, the functions of the variable frequency divider and the variable multiplier may be included in the frequency synthesizer.
FIG. 3 is a block diagram showing a third embodiment of the present invention in which a frequency synthesizer includes a frequency division number and a multiplication number setting function, and the same components as those described above (see FIG. 2) are denoted by the same reference numerals. In addition, “B” is attached after the reference numeral, and detailed description is omitted.
[0024]
In FIG. 3, the frequency synthesizer 1 </ b> B includes a basic oscillator 10, a variable multiplier 11, a phase comparator 12, a voltage controlled oscillator 13, and a variable frequency divider 14.
The output signal of the variable frequency divider 14 is applied to the output terminal 4 via the variable multiplier 7.
[0025]
The frequency control unit 5B controls the multiplication number M of the variable multiplier 7 and also controls the multiplication number P of the variable multiplier 11 and the frequency division number Q of the variable frequency divider 14 in the frequency synthesizer 1B.
The variable multiplier 11 multiplies the high frequency signal from the basic oscillator 10 by P and inputs it to the phase comparison circuit 12, and the variable frequency divider 14 divides the high frequency signal from the voltage controlled oscillator 13 by Q to obtain a phase comparison circuit. The phase comparison circuit 12 compares each high frequency signal and inputs an error component to the voltage controlled oscillator 13.
[0026]
Next, the operation according to the third embodiment of the present invention shown in FIG. 3 will be described.
The voltage controlled oscillator 13 inputs a high-frequency signal having a certain frequency to the variable frequency divider 14 and feeds back the high-frequency signal divided by 1 / Q to the phase comparison circuit 12.
The high frequency signal output from the variable frequency divider 14 is output from the output terminal 4 via the variable multiplier 7.
[0027]
At this time, the frequency control unit 5B outputs a control signal according to the frequency band of the voltage controlled oscillator 13, and controls the frequency division number Q of the variable frequency divider 14 and the frequency multiplication number M of the variable frequency multiplier 7.
Thus, by providing the variable frequency divider 14 in the frequency synthesizer 1B and including the function of the variable frequency divider 6 described above (see FIG. 2) in the frequency synthesizer 1B, the frequency divider can be reduced. In addition to the above effects, further downsizing can be realized.
Further, by using the voltage controlled oscillator (VCO) 13 as a high frequency oscillator, an on-chip voltage controlled oscillator (on-chip VCO) can be realized, and further miniaturization can be realized.
[0028]
Embodiment 4 FIG.
In the second and third embodiments, the oscillation frequencies of the frequency synthesizers 1A and 1B of the multiband receiver correspond to the highest frequency band among the plurality of communication systems. May be set higher.
In this way, by setting the oscillation frequency of the frequency synthesizer of the multiband receiver to be higher than the frequency band of the desired communication system, in addition to the above effects, the overall size of the multiband oscillator can be reduced. Can do.
[0029]
【The invention's effect】
As described above, according to the present invention, in a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems, the communication system having the highest frequency band among the plurality of communication systems. A corresponding frequency synthesizer, n two frequency dividers having different bandwidths and connected in parallel, n switches for switching n frequency dividers to connect to the frequency synthesizer, and n An output terminal connected to the n-th second frequency divider of the two-frequency divider, a frequency synthesizer and a frequency control unit for controlling the n switches, and the frequency variable range of the frequency synthesizer is octave The n number of divide-by-2 switches are selectively used by being switched by a switch, and a wide-band divide-by-2 can be connected to the oscillator. In an effect of realizing a multi-band oscillator having a desired band frequency bands of a plurality possible cover of a plurality of communication systems, a multi-band oscillator that achieves the cost and the size of the multi-band transceiver is obtained.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram showing a first embodiment of the present invention.
FIG. 2 is a block diagram showing a second embodiment of the present invention.
FIG. 3 is a block configuration diagram showing Embodiment 3 of the present invention.
[Explanation of symbols]
1, 1A, 1B frequency synthesizer, 2-1 to 2-n 2 frequency divider, 3-1 to 3-n switch, 4 output terminals, 5, 5A, 5B frequency control unit, 6, 14 variable frequency divider, 7 variable multiplier, 10 reference oscillator, 12 phase comparison circuit, 13 voltage controlled oscillator.

Claims (5)

In a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems,
A frequency synthesizer corresponding to a communication system having the highest frequency band among the plurality of communication systems;
N frequency dividers of different bandwidths and connected in parallel;
N switches for switching the n divide-by-2 and connecting to the frequency synthesizer;
An output terminal connected to an n-th two-divider of the n-dividers;
A frequency control unit for controlling the frequency synthesizer and the n switches,
The frequency variable range of the frequency synthesizer is set to octave,
The n-band divider is selectively used by being switched by the switch. In a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems,
A frequency synthesizer,
A variable frequency divider and a variable multiplier connected to the frequency synthesizer;
An output terminal connected to the variable multiplier;
A frequency control unit for controlling the frequency synthesizer, the variable frequency divider, and the variable multiplier;
The frequency division number of the variable frequency divider and the frequency multiplication number of the variable frequency multiplier are set in a frequency band of the plurality of communication systems under the control of the frequency control unit,
A frequency band in a desired communication system among the plurality of communication systems is set by the frequency synthesizer under the control of the frequency control unit. In a multiband oscillator used in a multiband transceiver corresponding to a plurality of frequency bands and a plurality of communication systems,
A frequency synthesizer,
A variable multiplier connected to the frequency synthesizer;
A phase comparison circuit, a voltage controlled oscillator and a variable frequency divider provided in the frequency synthesizer;
A frequency controller for controlling the variable multiplier and the variable frequency divider,
The number of multiplications of the variable multiplier and the number of divisions of the variable frequency divider are set to frequency bands of the plurality of communication systems under the control of the frequency control unit,
The voltage controlled oscillator inputs a high frequency signal based on the output signal of the phase comparison circuit to the variable frequency divider,
The output signal of the variable frequency divider is fed back to the phase comparison circuit,
A frequency band in a desired communication system among the plurality of communication systems is set by the frequency synthesizer under the control of the frequency control unit. 4. The multiband oscillator according to claim 2, wherein an oscillation frequency of the frequency synthesizer is set so as to correspond to a communication system having the highest frequency band among the plurality of communication systems. 5. 4. The multiband oscillator according to claim 2, wherein an oscillation frequency of the frequency synthesizer is set to a frequency higher than a frequency band of the desired communication system. 5.

Images