JP2000223954A - Even harmonic mixer, orthogonal mixer, even harmonic orthogonal mixer and direct conversion transmitter- receiver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform miniaturization and integration, to improve quadrature precision and to reduce the conversion loss by providing a balance/unbalance conversion circuit for a local oscillation wave(LO wave) obtained by forming two connection lines in a spiral shape and four anti-parallel diode pairs connected on a ring, etc. SOLUTION: An LO wave is subjected to balance/unbalance conversion by a spiral line and inputted to ring anti-parallel diode pairs 33a to 33d which are grounded at one point of connection points of two adjacent unit anti-parallel diode pairs. Next, an RF signal or a baseband signal is inputted to the pairs 33a to 33d from a connection point facing the ground point. Then, two waves inputted at the pairs 33a to 33d are subjected to frequency mixing. According to this configuration, since a spiral connection line is used as a balance/ unbalance conversion circuit for LO waves, miniaturization and integration can be performed, quadrature precision can be improved and the conversion loss can be reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention realizes a 90.degree. Distribution circuit for an RF signal with a small-sized and integrable configuration, and suppresses deterioration of the quadrature accuracy due to multiple reflection at an LO input terminal. The present invention relates to an even harmonic mixer, a quadrature mixer, an even harmonic quadrature mixer, and a direct conversion transceiver.

[0002]

2. Description of the Related Art FIG.
FIG. 1 is a configuration diagram of a conventional direct conversion receiver disclosed in Japanese Unexamined Patent Application Publication No. 2000-205,036. In the figure, reference numeral 16 denotes a received signal in the RF band of a frequency f _rf from an antenna (not shown)
F signal) and amplify it by a low noise amplifier (LN
A), the band pass filter 17 to retrieve a predetermined band signal from the output of the low noise amplifier 16 (BPF), 18 is by mixing the output signal and the frequency f _p of the band-pass filter 16, I baseband signal And a quadrature mixer for outputting a Q signal.

The quadrature mixer 18 includes a 90 ° distribution circuit 21 for dividing the output of the band-pass filter 17 into two, an in-phase distribution circuit 20 for dividing an external local oscillation wave into two,
The in-phase component output of the 90 ° distribution circuit 21 and the in-phase distribution circuit 2
A unit mixer 19 that mixes outputs of 0 and outputs an I signal
a, Quadrature output of 90 ° distribution circuit 21 and in-phase distribution circuit 20
Unit mixer 19 that mixes the output of
b.

Reference numeral 22 denotes a local oscillator (LO) that generates a local oscillation wave (hereinafter, LO wave) and supplies it to the quadrature mixer 18. Reference numerals 23a and 23b denote low-pass filters (LPF) for extracting low-frequency signals, 24a and 24b denote baseband amplifiers for amplifying the outputs of the low-pass filters 23a and 23b, and 25a and 25b denote baseband amplifiers 24a and 24b. An AD converter for converting the output from analog to digital, respectively, 26 is an AD converter 25
a demodulation operation circuit that performs demodulation processing based on the data of the I signal and the data of the Q signal output by the signals a and 25b.

Next, the operation will be described. FIG. 8 is a configuration diagram showing a quadrature mixer used in a conventional direct conversion receiver. In a conventional direct conversion receiver shown in FIG. 7, the received wave f _rf by quadrature mixer shown in FIG. 8, I signal of a frequency f _rf -f _p, is the complex envelope detection to the Q signal. Next, the orthogonal mixers 18
The two RF signals distributed with a phase difference of 0 ° and the LO waves distributed in the same phase are respectively analog-multiplied,
Mix frequencies.

[0006] Here, the frequency f _p of the LO wave, if almost the same as the frequency f _rf of the RF signal, the low-pass filter 23a, a 23b, a quadrature mixer 18 I outputs and Q
The output is filtered, and the frequency component f _bb of the difference between f _p and f _rf near the baseband frequency is extracted to obtain a modulated signal component of the received wave (RF). These I and Q outputs are connected to baseband amplifiers 24a and 24b.
After the signal is amplified by the A / D converter, the A / D converter 25
a and 25b respectively. The demodulation operation circuit 26 reproduces data modulated into a received wave based on the I signal and the Q signal.

FIG. 9 is a block diagram showing an even harmonic quadrature mixer used in a conventional even harmonic direct conversion receiver. As quadrature mixer, as shown in FIG. 10, the case of using an even harmonic mixer for frequency mixing in the second harmonic of the LO wave, wherein a frequency 2f _p of the second harmonic of the LO wave, RF signal if substantially the frequency f _rf of the same, by a low-pass filter, the I and Q outputs of quadrature mixer respectively filtered, the baseband frequency near 2f _p and difference frequency components f and f _rf By extracting _bb , a modulated signal component of the received wave (RF) is obtained.

[0008] An even harmonic direct conversion receiver using such an even harmonic quadrature mixer is shown in FIG.
Compared with the direct conversion receiver using the fundamental wave mixer shown in (1), the frequency of the RF signal is different from that of the LO wave, so that there is little interference between the RF signal and the LO wave. In addition, when the even harmonic direct converter is applied to the transmitter, there is an advantage that carrier leakage can be suppressed. However, such a conventional even harmonic direct conversion receiver requires a 90 ° distribution circuit to form an even harmonic quadrature mixer.

FIG. 10 is a block diagram showing a conventional Lange coupler used as a 90 ° distribution circuit. E. FIG. "Foundations f" by Collin
11 is a configuration diagram showing a Lange coupler described in “microwave engineering” on page 435. In FIG. 10, 3, 4, 5, and 6 indicate input / output terminals, respectively.

A Lange coupler as shown in FIG.
When trying to configure in the Hz band, 1 /
The line length of the four-wavelength coupled line is approximately 7.5 mm. Even when a dielectric substrate material having a dielectric constant of 10 is used,
The line length of the coupling line is approximately 2.3 mm. Therefore, the entire circuit requires a length of about 4.6 mm, and if integration is assumed, the chip area becomes large, which is not practical.

As compared with the case where a Lange coupler is used, a method for reducing the size of a 90 ° distribution circuit is shown in FIG.
As shown in FIG. 1, there is known a spirally coupled line type distribution circuit using two coupled lines. FIG. 11 is a configuration diagram showing a conventional spiral 90 ° distribution circuit in which two coupled lines are formed in a spiral shape. For example, there is a configuration described in the 1996 IEICE General Conference C-131.

In FIG. 1, reference numeral 1 denotes a 90 ° hybrid circuit in which two coupling lines are formed in a spiral shape.
This is the line connected to the innermost part of the spiral shape of the coupled lines (hereinafter, this line is referred to as line 1).
And). Reference numeral 2 denotes the other of the two coupled lines (hereinafter, this line is referred to as line 2). 3,4,5,6
Are input / output terminals of the spirally coupled line.

In such a spiral 90 ° distribution circuit, when the number of turns of the spiral shape can be reduced by using a high dielectric constant, the path difference between the two lines is sufficiently small and good phase accuracy can be obtained. . However, when a substrate having a low dielectric constant is used and used at a low frequency, the path difference between the two coupled lines becomes large, and as shown in FIG.
There is a problem that the frequency at which the degree of coupling is maximum is shifted from the frequency at which the phase difference is 90 °. FIG. 12 is a characteristic diagram showing characteristics of a conventional spiral 90 ° distribution circuit.

FIG. 13 is a characteristic diagram showing the characteristics of the conventional in-phase distribution circuit. As shown in FIG. 13, the center frequency of the balun used for the input terminal of the LO wave of the even harmonic quadrature mixer is changed to the LO frequency. When the frequency is set to the frequency, the RF signal is not synthesized in the opposite phase on the input terminal side of the LO wave, so that the RF reflected wave generated at the input terminal of the LO wave causes deterioration of the isolation characteristic, and as a quadrature mixer, There is a problem that the orthogonal accuracy is deteriorated.

Further, a lumped-constant-type Wilkinson power distribution circuit as shown in FIG. 14 is generally used as the in-phase distribution circuit for the LO wave of the even harmonic quadrature mixer.
FIG. 14 is a circuit diagram showing a conventional lumped Wilkinson power distribution circuit. 7 is an input terminal, 8a and 8b are distribution output terminals respectively connected to the inductors 11a and 11b, 9 is a capacitor shunt-connected to the input terminal 7,
11a and 11b are inductors connected to the input terminal 7,
10a and 10b are capacitors shunt-connected to the connection points between the inductors 11a and 11b and the output terminals 8a and 8b.

In an ordinary Wilkinson power distribution circuit as shown in FIG. 14, in the case of an even harmonic mixer, the isolation between the distribution output terminals is close to twice the frequency of the LO wave which is the frequency of the RF signal. small. Therefore,
There is a problem that isolation characteristics deteriorate due to multiple reflection of the RF signal at the input terminal of the LO wave, and the orthogonal accuracy deteriorates.

[0017]

The conventional even-harmonic mixer, quadrature mixer, even-harmonic quadrature mixer and direct-conversion transceiver are constructed as described above. In the distribution circuit, the area of the circuit board is large, and miniaturization and integration are difficult, and the isolation between the RF signal and the LO wave is deteriorated, and between the unit mixers provided for the I signal and the Q signal, respectively. When RF signal interference occurs, there has been a problem that orthogonal accuracy deteriorates and communication quality deteriorates.

Further, the spiral 90 ° distribution circuit has a problem that the frequency at which the degree of coupling is maximum is shifted from the frequency at which the phase difference is 90 °.

Further, when the center frequency of the balun used for the input terminal of the LO wave of the even harmonic quadrature mixer is set to the frequency of the LO wave, the isolation characteristic deteriorates, and the quadrature accuracy as the quadrature mixer deteriorates. There were issues such as.

Further, in a normal Wilkinson power distribution circuit, in the case of an even harmonic mixer, in the vicinity of twice the frequency of the LO wave, which is the frequency of the RF signal, due to the multiple reflection of the RF signal at the input terminal of the LO wave. In addition, there are problems such as deterioration of isolation characteristics and deterioration of orthogonal accuracy.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems. By reducing the size of a 90 ° distribution circuit for RF signals, the area of a circuit board is reduced, and miniaturization and integration are achieved. It is an object to obtain an even harmonic mixer, a quadrature mixer, and an even harmonic quadrature mixer.

In addition, when the isolation between the RF signal and the LO wave is deteriorated and the RF signal interferes between the unit mixers provided for the I signal and the Q signal, the deterioration of the quadrature accuracy and the communication quality are caused. It is an object of the present invention to obtain an even harmonic mixer, a quadrature mixer, an even harmonic quadrature mixer, and a direct conversion transceiver capable of suppressing the deterioration of the signal.

Further, in the spiral 90 ° distribution circuit, the frequency at which the degree of coupling is maximum and the phase difference are 90 °
It is an object of the present invention to obtain an even harmonic mixer, a quadrature mixer, and an even harmonic quadrature mixer that can prevent the occurrence of

Further, even when the center frequency of the balun used for the input terminal of the LO wave of the even harmonic quadrature mixer is set to the frequency of the LO wave, the even harmonic mixer which prevents the deterioration of the quadrature accuracy as the quadrature mixer, the quadrature mixer, It is an object to obtain a mixer, an even harmonic quadrature mixer, and a direct conversion transceiver.

Further, even in the case of an even harmonic mixer of a normal Wilkinson power distribution circuit, an even harmonic mixer, a quadrature mixer, an even harmonic quadrature mixer and a direct conversion transceiver for preventing the deterioration of the quadrature accuracy can be obtained. Aim.

[0026]

The even harmonic mixer according to the present invention uses a spirally coupled line formed by forming two coupled lines in a spiral as a balanced-unbalanced conversion circuit for a local oscillation wave. One end of each of the outputs is connected to a capacitor, and the other end of the capacitor is connected to a two-way distribution circuit. The two anti-parallel diode pairs are connected on a ring. A ring anti-parallel diode pair is connected to each of the two output terminals, a via hole is connected to another connection point of the ring anti-parallel diode pair, and a high-frequency signal and a base connected to another connection point of the anti-parallel diode pair are connected. The band signal or the intermediate frequency signal is demultiplexed by the demultiplexer, and the input / output terminal of the high frequency signal is connected to the demultiplexer. It continued to, those having the input and output terminals of the baseband signal or an intermediate frequency.

The even harmonic mixer according to the present invention has a balanced-
In the 90 ° hybrid circuit in which two coupling lines are formed in a spiral shape in the unbalanced conversion circuit, one input / output terminal connected to the outermost line in the spiral shape is connected to the final end of the innermost line in the spiral shape. At the same time, the other input / output terminal connected to the second outermost line of the spiral shape is connected to the final end of the second innermost line of the spiral shape, and the line lengths of the two coupled lines are equal. Thus, the inner diameter and the outer diameter of the spiral shape are optimized.

The even harmonic mixer according to the present invention has a balanced-
In the unbalanced conversion circuit, the inside of the spiral-shaped coupling line is wound once around an appropriate length to further correct the line length.

The even harmonic mixer according to the present invention has a balanced-
The center frequency of the unbalanced conversion circuit is set to an intermediate value between the frequency of the local oscillation wave and the frequency of the high-frequency signal.

According to a second aspect of the present invention, there is provided an even-harmonic quadrature mixer in which the balanced-unbalanced conversion circuit according to the second or third aspect is provided at an input / output terminal of a high-frequency signal, and a capacitor shunt-connected to the input terminal. , Two inductors having one terminal connected to the input terminal, two distribution output terminals connected to the other terminal of the two inductors, a resistor inserted between the distribution output terminals, and a distribution output terminal. At a predetermined frequency, it operates as a shunt capacitor of the Wilkinson power divider, and at a frequency higher than the desired frequency, a series resonance circuit whose element value is selected so as to form a series resonance. A lumped constant type common-mode distributor is provided at an input terminal of a local oscillation wave, and the even harmonic mixer according to claim 1 is used as a unit mixer. It is obtained by using Te.

A direct conversion transceiver according to the present invention uses the even harmonic quadrature mixer according to claim 5 as a quadrature mixer for modulation and demodulation.

According to a quadrature mixer according to the present invention, the balanced-unbalanced conversion circuit according to claim 2 or 3 is provided at an input / output terminal of a high-frequency signal.

A direct conversion transceiver according to the present invention uses the quadrature mixer according to claim 7 as a quadrature mixer for modulation and demodulation.

[0034]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below. Embodiment 1 FIG. FIG. 1 is a block diagram of a first embodiment of the present invention.
FIG. 2 is a configuration diagram illustrating a 0 ° power distribution circuit, where 1
Is a line connected to the innermost part of the spiral shape of the two coupled lines constituting the 90 ° hybrid circuit in which the two coupled lines are formed in a spiral shape (hereinafter, this line is referred to as a line). 1). Reference numeral 2 denotes the other of the two coupled lines (hereinafter, this line is referred to as line 2
And). Reference numerals 3, 4, 5, and 6 are input / output terminals of the spiral coupling line.

In the conventional spiral hybrid circuit, as shown in FIG. 11, the line 2 is the outermost line of the spiral shape. Therefore, the line 1 has a shorter path length than the line 2 in any round of the spiral shape, and the larger the number of turns of the spiral shape, the larger the path difference between the two lines.

Next, the operation will be described. As shown in FIG. 12, in the conventional 90 ° power distribution circuit, the frequency at which the phase difference of 90 ° is different from the frequency at which the degree of coupling is maximum becomes large.
The phase error is likely to deteriorate. On the other hand, according to the 90 ° distribution circuit according to the first embodiment, the line 1 is wound around the outermost periphery as shown in FIG. Since the path difference of the line 2 is corrected, the path difference between the line 1 and the line 2 can be reduced. Further, even in the case of being arranged on the outermost periphery, the adjacent lines 1 and 2 can always be arranged alternately.

As described above, according to the first embodiment, the line 1 is wound around the outermost periphery, and the lines 1 and 2 are alternately arranged, so that the coupling between the two lines is increased, and the amplitude error is increased. Further, effects such as suppression of deterioration of the phase error can be obtained.

Further, by optimizing the inner diameter and the outer diameter of the spiral shape so that the length of the outermost line 1 is optimized at a desired frequency in accordance with the path difference between the line 1 and the line 2, As shown in FIG. 12, the phase difference can be set to 90 ° at the frequency where the degree of coupling of the two lines is the maximum, and effects such as maintaining good characteristics can be obtained.

Embodiment 2 FIG. 2 is a configuration diagram showing a 90 ° power distribution circuit according to Embodiment 2 of the present invention. In the figure, the same reference numerals as those in Embodiment 1 denote the same or corresponding parts, and a description thereof will be omitted. Embodiment 1
In the above, the line 1 was wound around the outermost periphery, and the line 1 and the line 2 were alternately arranged. However, in the second embodiment, in order to correct the path length of the two lines, By making the shape further wrapped around the innermost circumference, effects such as suppression of deterioration of amplitude error and phase error can be obtained.

Embodiment 3 FIG. 3 is a circuit diagram showing an in-phase distribution circuit according to Embodiment 3 of the present invention. In FIG. 3, reference numeral 7 denotes an input terminal, and 8a and 8b denote inductors 11a and 1b.
1b, a distribution output terminal respectively connected to 1b, a capacitor 9 shunt-connected to the input terminal 7, 11a, 11b inductors connected to the input terminal 7, 13a, 13b inductors 11a, 11b and output terminals 8a, 8b. A series resonant circuit composed of inductors 14a, 14b and capacitors 15a, 15b shunt-connected to a connection point;
4a and 14b are inductors constituting the series resonance circuits 13a and 13b, and 15a and 15b are series resonance circuits 13a and 1b.
3B shows a capacitor constituting 3b.

Next, the operation will be described. As shown in FIG. 14, in the conventional lumped Wilkinson power divider, when the LO frequency is f _0, each parameter in FIG. 14 is determined as follows.

Z_iso= 2Z_out  Z₀= √ (Z_in・ Z_iso) C_p= 1 / (2π · f₀・ Z₀) L_S= Z₀/ (2π · f₀(1)

[0043] 3, in the Wilkinson power divider according to the present invention, the frequency f _BRF required between the distribution terminal, the resonant frequency of the series resonant circuit, the following equation using the parameters in Fig. 3 Given to.

F _brf = 1 / 2π · √ (L _brf · C _brf ) (2)

On the other hand, the series resonance circuits 13a and 13b
In O frequencies, it is necessary to capacity behaves as a capacitor of _{C p, C p, L brf} , relationship C _BRF is expressed by the following equation.

1 / (2π · f ₀ · C _p ) = 2π · f ₀ · L _brf + 1 / (2π · L _brf · C _brf ) (3)

Therefore, from the relationship between f ₀ and f _brf ,
Equation (2), using equation (3), may be determined C _{br f} and L _BRF. For example, in an even harmonic mixer, f
Since _brf = 2f _0,

[0048] ^{_{L brf = 1 / (20π 2}} · f 0 2 · C p) C brf = 5C p / 4 (4)

As described above, according to the third embodiment, the Wilkinson power divider operates as a shunt capacitor of the Wilkinson power divider at a desired frequency as an element value of the series resonance circuit, and operates at a desired frequency. Since the element value was selected so as to be in series resonance at an arbitrary high frequency, for example, twice the desired frequency, the LO
The effect of improving the isolation characteristic at twice the frequency, that is, at the RF frequency in the in-phase distribution circuit can be obtained.

Embodiment 4 FIG. 4 is a configuration diagram showing an even harmonic mixer according to Embodiment 4 of the present invention. In FIG. 4, reference numeral 28 denotes an RF signal input / output terminal, 29 denotes a baseband signal input / output terminal, 30a and 30b denote capacitors, 3
Reference numeral 1 denotes a spiral coupling line as shown in FIGS. 1, 2 and 12, and is used as a LO-wave balanced-unbalanced conversion circuit (hereinafter, balun). 32 is a local oscillation wave input terminal, 33a, 33b, 33c and 33d are ring anti-parallel diode pairs consisting of four anti-parallel diode pairs connected in a ring, and 34 is a component for demultiplexing an RF signal and a baseband signal. It is a wave circuit.

Next, the operation will be described. In the even harmonic mixer shown in FIG.
Are converted to balanced-unbalanced, and are input to the ring anti-parallel diode pairs 33a to 33d grounded at one connection point of two adjacent unit anti-parallel diode pairs. Next, an RF signal or a baseband signal is input to these ring anti-parallel diode pairs 33a to 33d from a connection point opposite to the ground point. Then, the ring anti-parallel diode pairs 33a-3
The two waves (LO wave and RF signal or LO wave and baseband signal) input at 3d are frequency-mixed. However,
In the case of a mixer using a ring anti-parallel diode, the frequency mixing is performed using even harmonics of the LO wave as a fundamental mode. Therefore, the frequency of the most strongly output, f _rf ± 2f _p or consists either of f _bb ± 2f _p.

In the fundamental wave mixer having a balanced configuration as shown in FIG. 8, the RF signal frequency component flowing through the diode is used as an LO balun because the RF frequency is close to the LO wave frequency. After being divided into two components having opposite phases by a spiral coupling line, they are combined at the input terminal of the LO wave. Therefore, at the LO input terminal,
The two components of the F signal are canceled and are not output. Therefore, there is a feature that the leakage of the RF power to the LO terminal does not cause the conversion loss or the deterioration of the isolation between the RF signal and the LO wave.

On the other hand, when the even harmonic mixer has a balanced configuration as shown in FIG. 9, the frequency of the LO wave is about half the frequency of the RF signal. When optimized, RF input terminal of LO wave
The signals do not become out of phase, and the RF signal leaks to the LO terminal. Therefore, the conversion loss and the RF signal -L
Degradation of isolation between O waves occurs.

As described above, according to the fourth embodiment, in the even harmonic mixer shown in FIG. 4, in order to solve such a problem, a spiral balun using two coupled lines as the LO balun is used. , The center frequency of the balun is set between the LO frequency and the RF signal frequency, and the balanced-to-unbalanced conversion characteristic is obtained over a wide band. And cancel each other, so that the above-mentioned problem can be suppressed.

Further, as the balun used in the fourth embodiment, a spirally coupled line in which the difference between the line lengths of the two lines is corrected as described in the first and second embodiments is used. It is possible to obtain better balance-unbalance conversion characteristics than when using a spiral balun with two coupled lines, reduce conversion loss, and improve isolation characteristics between LO waves and RF signals. And the like.

Embodiment 5 FIG. 5 is a configuration diagram showing an even harmonic quadrature mixer according to a fifth embodiment of the present invention. In the figure, the same reference numerals as those in the third and fourth embodiments denote the same or corresponding parts, and a description thereof will be omitted. 35
Is the 90 ° hybrid circuit according to the first embodiment,
36 is an RF signal input terminal, 37a and 37b are unit even harmonic mixers according to the fourth embodiment, 38 is a terminating resistor used in a 90 ° hybrid circuit, 39 is an LO wave input terminal, and 40 is the above embodiment. 15 is a Wilkinson power divider according to a third embodiment.

Next, the operation will be described. In the even-harmonic quadrature mixer shown in FIG. 5, as described in the first embodiment, the 90 ° hybrid circuit 35 having a small configuration is used, and the RF signal in the Wilkinson power divider used for distribution of LO waves is used. In addition, in the unit even harmonic mixer, by setting the center frequency of the LO balun between the LO frequency and the RF frequency, the conversion loss is reduced, and the isolation between the RF and LO is reduced. Improve the characterization characteristics.

As described above, according to the fifth embodiment, effects such as improvement of orthogonal accuracy can be obtained with a configuration that can be downsized.

Embodiment 6 FIG. FIG. 6 is a configuration diagram showing an even harmonic quadrature mixer according to a sixth embodiment of the present invention. In the figure, the same reference numerals as those in the fifth embodiment denote the same or corresponding parts, and a description thereof will be omitted. Reference numeral 41 denotes a 90 ° hybrid circuit according to the second embodiment.

Next, the operation will be described. In the even harmonic quadrature mixer shown in FIG. 6, as in the fifth embodiment, a 90 ° hybrid circuit 41 having a small configuration is used, and
R at Wilkinson power divider used for LO wave distribution
The isolation characteristic of the F signal is improved, and the center frequency of the LO balun is set to L even in the unit even harmonic mixer.
It is set between the O frequency and the RF frequency.

As described above, according to the sixth embodiment, the conversion loss can be reduced and the RF
By improving the isolation characteristics between -LO, an effect such as improvement in orthogonal accuracy can be obtained with a configuration that can be downsized. Further, effects such as obtaining better phase accuracy than in the case of the fifth embodiment can be obtained.

Embodiment 7 In the seventh embodiment, the orthogonal mixer 18 of FIG. 7 is replaced by the orthogonal mixer used in FIG. 10 or FIG. In the direct converter according to the seventh embodiment, the even-harmonic quadrature mixer, which can be downsized, can be downsized as a whole, and a direct conversion receiver without deterioration in communication quality due to deterioration in orthogonal accuracy is configured. And the like.

In the above description, a direct conversion receiver has been described as an example. However, even when a direct conversion transmitter is used, good modulation accuracy can be obtained and low carrier leakage power can be obtained. The same effect as in the case of is achieved.

[0064]

As described above, according to the present invention, a spirally coupled line in which two coupled lines are formed in a spiral shape is used as a local oscillation wave balanced-unbalanced conversion circuit. Connect one end to the capacitor
A two distribution circuit is connected to the other end of the capacitor, and four antiparallel diode pairs are connected on the ring. Two opposing connection points are connected to two output terminals of the two distribution circuits by ring antiparallel diode pairs. Each is connected, a via hole is connected to the other connection point of the ring anti-parallel diode pair, and the high-frequency signal and the baseband signal or the intermediate frequency signal connected to the other connection point of the anti-parallel diode pair are demultiplexed. The input / output terminal of the high frequency signal is connected to this demultiplexing circuit, and the input / output terminal of the baseband signal or the intermediate frequency is provided, so that the configuration can be downsized and integrated. There is an effect that the orthogonal accuracy can be improved and the conversion loss can be reduced.

According to the present invention, in the balanced-unbalanced conversion circuit, two coupled lines are formed in a spiral shape.
° In the hybrid circuit, connect one input / output terminal connected to the outermost line of the spiral shape to the final end of the innermost line of the spiral shape, and connect the last At the end, connect the other input / output terminal connected to the second line from the outermost of the spiral shape, and optimize the inner and outer diameters of the spiral shape so that the line lengths of the two coupled lines are equal. Therefore, there is an effect that the phase accuracy can be improved with a configuration that can be miniaturized and integrated.

According to the present invention, in the balanced-unbalanced conversion circuit, the inside of the spiral-shaped coupling line is wound around the circuit with an appropriate length to further correct the line length, so that the size and integration can be reduced. With such a configuration, the phase accuracy can be improved.

According to the present invention, the center frequency of the balanced-unbalanced conversion circuit is set to an intermediate value between the frequency of the local oscillation wave and the frequency of the high-frequency signal. There is an effect that the orthogonal accuracy can be improved and the conversion loss can be reduced.

According to the present invention, the balanced-unbalanced conversion circuit according to claim 2 or 3 is provided at the input / output terminal of a high-frequency signal, and a capacitor shunt-connected to the input terminal and one of the input terminals , Two distribution output terminals connected to the other terminals of the two inductors, a resistor inserted between the distribution output terminals, and a shunt connection to the distribution output terminals. A lumped constant type consisting of an inductor and a capacitor, which operates as a shunt capacitor of the Wilkinson power divider at a predetermined frequency, and a series resonance circuit whose element value is selected to be a series resonance at a frequency higher than a desired frequency. An in-phase distributor is provided at the input terminal of the local oscillation wave, and the even harmonic mixer according to claim 1 is used as a unit mixer. Since the, compact, with integration configurable, it is possible to improve the orthogonal accuracy,
There is an effect that the conversion loss can be reduced.

According to the present invention, since the even harmonic quadrature mixer according to claim 5 is used as a quadrature mixer for modulation and demodulation, there is an effect that communication quality can be improved.

According to the present invention, since the balanced-unbalanced conversion circuit according to claim 2 or 3 is provided at the input / output terminal of the high-frequency signal, it is possible to reduce the size and integrate the circuit, and to obtain the orthogonal precision. And the conversion loss can be reduced.

According to the present invention, since the direct conversion transceiver uses the quadrature mixer according to claim 7 as a quadrature mixer for modulation and demodulation, it is possible to improve the communication quality.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a 90 ° power distribution circuit according to Embodiment 1 of the present invention.

FIG. 2 is a configuration diagram showing a 90 ° power distribution circuit according to a second embodiment of the present invention.

FIG. 3 is a circuit diagram showing an in-phase distribution circuit according to Embodiment 3 of the present invention.

FIG. 4 is a configuration diagram showing an even harmonic mixer according to Embodiment 4 of the present invention.

FIG. 5 is a configuration diagram showing an even harmonic quadrature mixer according to a fifth embodiment of the present invention.

FIG. 6 is a configuration diagram showing an even harmonic quadrature mixer according to a sixth embodiment of the present invention.

FIG. 7 is a configuration diagram of a conventional direct conversion receiver.

FIG. 8 is a configuration diagram showing a quadrature mixer used in a conventional direct conversion receiver.

FIG. 9 is a configuration diagram showing an even harmonic quadrature mixer used in a conventional even harmonic waveform direct conversion receiver.

FIG. 10 is a configuration diagram showing a conventional Lange coupler used as a 90 ° distribution circuit.

FIG. 11 is a configuration diagram showing a conventional spiral 90 ° distribution circuit in which two coupled lines are formed in a spiral shape.

FIG. 12 is a characteristic diagram showing characteristics of a conventional spiral 90 ° distribution circuit.

FIG. 13 is a characteristic diagram showing characteristics of a conventional in-phase distribution circuit.

FIG. 14 is a circuit diagram showing a conventional lumped constant type Wilkinson power divider.

[Explanation of symbols]

1, 2 coupling line, 3, 4, 5, 6 input / output terminal of spiral coupling line, 7 input terminal of common mode distribution circuit, 8a, 8
b Output terminal of common mode distribution circuit, 9, 10a, 10b, 1
5a, 15b, 30a, 30b capacitors, 11a,
11b, 14a, 14b inductor, 12 resistance, 1
3a, 13b Series resonance circuit, 18 quadrature mixer, 19
a, 19b unit mixer, 20 in-phase distribution circuit, 21
90 ° distribution circuit, 31 balanced-unbalanced conversion circuit, 33a
~ 33d Anti-parallel diode pair, 37a, 3
7b Unit even harmonic mixer.

Claims (8)

[Claims] 1. A balanced-unbalanced conversion circuit for a local oscillation wave in which two coupled lines are formed in a spiral shape; a capacitor having one end connected to each output terminal of the balanced-unbalanced conversion circuit; A two-divider circuit connected to the other end of the capacitor, and a ring composed of four anti-parallel diode pairs connected on the ring, and two opposite connection points connected to two output terminals of the two-divider circuit, respectively. An anti-parallel diode pair, a via hole connected to another connection point of the ring anti-parallel diode pair, a high-frequency signal and a baseband signal or an intermediate frequency signal connected to another connection point of the anti-parallel diode pair. A branching circuit for branching the baseband signal, a high-frequency signal input / output terminal connected to the branching circuit, and a baseband signal. Even harmonic mixer stomach with the input and output terminals of the intermediate frequency. 2. The balanced-unbalanced conversion circuit includes a spiral-shaped outermost line at the final end of a spiral-shaped innermost line of a 90 ° hybrid circuit in which two coupled lines are formed in a spiral shape. And one of the input / output terminals connected to the spiral-shaped innermost line and the other end connected to the spiral-shaped outermost second line. 2. The even harmonic mixer according to claim 1, wherein the inner diameter and the outer diameter of the spiral shape are optimized such that the line lengths of the coupled lines are equal. 3. The even harmonic mixer according to claim 1, wherein the balanced-to-unbalanced conversion circuit further includes a spiral-shaped inner coupling line that is wound once around an appropriate length to further correct the line length. . 4. The center frequency of the balanced-unbalanced conversion circuit is
2. The even harmonic mixer according to claim 1, wherein the even harmonic mixer is set to an intermediate value between the frequency of the local oscillation wave and the frequency of the high frequency signal. 5. A balanced-unbalanced conversion circuit according to claim 2 or 3 is provided at an input / output terminal of a high-frequency signal, and a capacitor shunt-connected to an input terminal is connected to said input terminal and one terminal. Two connected inductors, two distributed output terminals connected to the other terminals of the two inductors, a resistor inserted between the distributed output terminals, an inductor shunt-connected to the distributed output terminals, Consisting of a capacitor, at a predetermined frequency, operates as a shunt capacitor of the Wilkinson power divider,
2. The even harmonic according to claim 1, wherein a lumped-constant common-mode distributor including a series resonance circuit whose element value is selected so as to have series resonance at a frequency higher than a desired frequency is provided at an input terminal of the local oscillation wave. An even harmonic quadrature mixer using a wave mixer as a unit mixer. 6. A direct conversion transceiver using the even harmonic quadrature mixer according to claim 5 as a quadrature mixer for modulation and demodulation. 7. A quadrature mixer characterized in that the balanced-unbalanced conversion circuit according to claim 2 is provided at an input / output terminal of a high-frequency signal. 8. A direct conversion transceiver using the quadrature mixer according to claim 7 as a quadrature mixer for modulation and demodulation.