JP2005303441A - Wideband 45° phase shifter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To realize a 45° phase shifter in which the input signal frequency is close to a local oscillation frequency and power consumption is low. <P>SOLUTION: Using three 1/2 frequency dividers, signals having a frequency of 1/4 and phases of 0° and 45°, and 90° and 135° for an input signal are multiplied by signals having a frequency of 1/2 and phases of 0° and 270° for the input signal. Subsequently, the set of 0° and 90° and the set of 45° and 135° are summed to produce output signals having a phase difference of 45°. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

The present invention relates to a phase shifter circuit used in a wireless communication device.

  Direct conversion is a method of directly converting an RF signal into a baseband signal, and is also called direct conversion, homodyne, or zero INF. As a mixer suitable for the direct conversion system, an even harmonic mixer as shown in the following “Patent Document 1” is known. The even harmonic mixer mixes the second harmonic of the local oscillation signal with the high frequency signal. A quadrature demodulator using an even harmonic mixer is shown in FIG. In FIG. 4, a modulated signal modulated at a high frequency input from an input terminal 51 is input to an orthogonal demodulator 54. This input signal is divided into two, and one signal is input to the even harmonic mixer 55 and the other signal is input to the even harmonic mixer 56. The output signal of the local oscillator 57 is input to the 45 ° phase shifter 58, and two signals of 0 ° and 45 ° are output with an equal amplitude and a phase difference of 45 °.

  One of the output signals of the 45-degree phase shifter 58 is input to the even harmonic mixer 55 as a local oscillation signal, multiplied by the modulated signal, and the high-frequency component is removed by the low-pass filter 59, and the baseband in-phase signal is output. The signal is output to the output terminal 52. Of the output signal of the 45-degree phase shifter 58, the signal whose phase has been changed by 45 degrees is input to the even harmonic mixer 56 as a local oscillation signal and multiplied by the modulated signal, and the low-pass filter 60 performs high-frequency components. And the baseband quadrature signal is output to the output terminal 53. The even harmonic mixers 55 and 56 mix the second harmonic of the output signal of the local oscillator 57 and the high-frequency signal that is the modulated signal, so that a quadrature demodulation is performed by giving a 45-degree phase difference to the local oscillation signal. Is possible.

  FIG. 5 shows a quadrature modulator using an even harmonic mixer. In FIG. 5, unlike the demodulator in FIG. 4, the input signal is applied to the input terminals 72 and 73 on the right side of FIG. The baseband in-phase signal input from the input terminal 72 is input to the even harmonic mixer 75 via the low pass filter 79. The output signal of the local oscillator 77 is input to the 45-degree phase shifter 78, and two signals having the same amplitude and a phase difference of 45 degrees are output.

  One of the output signals of the 45-degree phase shifter 78 (in-phase 0 ° in the case of FIG. 5) is input to the even harmonic mixer 75 as a local oscillation signal and multiplied by the output signal of the low-pass filter 79. On the other hand, the baseband orthogonal signal input from the input terminal 73 is input to the even harmonic mixer 76 via the low pass filter 80. Of the output signal of the 45-degree phase shifter 78, the signal whose phase is changed by 45 degrees is input to the even harmonic mixer 76 as a local oscillation signal and multiplied by the output signal of the low-pass filter 80. The output signals of the even harmonic mixer 75 and the even harmonic mixer 76 are added by an adder 81, and the output signal of the quadrature modulator 74 is output to the output terminal 71 as a modulated signal that has been quadrature modulated at a high frequency. Since the even harmonic mixer mixes the second harmonic of the local oscillation signal and the baseband signal, quadrature modulation can be performed by giving a phase difference of 45 degrees to the local oscillation signal.

  A 45-degree phase shifter used for such a quadrature modulator or a quadrature demodulator uses a circuit in which a resistance element and a capacitor are combined as disclosed in the following “Non-patent Document 1” to “Non-patent Document 3” Has been.

  Capacitors and inductors have impedances that change with frequency. Therefore, any circuit in which these resistance elements and capacitors or resistance elements and inductors are combined has a drawback that the phase difference or amplitude error changes with frequency and the frequency band is narrow.

On the other hand, as a 90-degree phase shifter that gives a phase difference of 90 degrees instead of 45 degrees to the local oscillation signal, a method using a 1/2 frequency divider is widely used. The configuration is shown in FIG. 6 and the operation is shown in FIG. In FIG. 6, reference numeral 100 denotes a first D flip-flop, 101 denotes a second D flip-flop, and 102 denotes an inverter circuit. As shown in FIG. 7, the output signal obtained by inverting the polarity of the logic output high or low for each fall of the signal inputted from the terminal V _in is output from the output terminal V _0. The output signal obtained by inverting the logic output high or low for each rising edge of the input from the input terminal V _in signal is output from the output terminal V _90. Further, the inverted output of the signal output from the output terminal V ₀ is output to the output terminal V ₁₈₀ , and the inverted polarity output of the signal output from the output terminal V ₉₀ is output to the output terminal V ₂₇₀ . Therefore when the duty ratio of the input from the input terminal _{V in} signal is 50%, the output terminal _{V 0,} V _90, V _180, signals the phase of the output from the _{V 270} 0 degrees, 90 degrees, 180 degrees, 270 Degree. The frequency of these output signals is ½ of the signal input from the input terminal V _in . Such a 90 degree phase shifter operates in the entire range in which the frequency dividing operation is possible, and has a wide band characteristic. However, if a 45-degree phase shifter is to be constructed using a frequency divider, it is necessary to further connect ½ frequency dividers in cascade to form a ¼ frequency divider. Therefore, an input signal having a frequency four times the required local oscillation frequency is required. For example, when a local oscillation frequency of 3 GHz is required, the input frequency to the frequency divider is 12 GHz, and the power consumption of the frequency divider and the local oscillator is increased.

Japanese Patent No. 3252539 T. Yamaji, H. Tanimoto, and H. Kokatsu, “An I / Q active balanced harmonic mixer with IM2 cancelers and a 45 ° phase shifter,” IEEE J. Solid-State Circuits vol.33, no.12, pp. 2240-2246, Dec. 1998. L. Sheng, J. jensen, and LELarson, “A wide-bandwidth Si / SiGe HBT direct conversion sub-harmonic mixer / downconverter,” IEEE J. Solid-State Circuits, vol.35, no.9, pp.1329 -1337, Sept. 2000 M. Kawashima, T. Nakagawa, H. Hayashi, K. Nishikawa and K. Araki, “A 0.9-2.6GHz broadband RF front-end chip-set with a direct conversion architecture,” IEICE Trans. Commun., Vol.E85 -B, no.12, pp.22732-2740, Dec. 2002

  As described above, the 45-degree phase shifter in which the conventional resistance element and the capacitor are combined has a problem that the phase difference or the amplitude error changes with the frequency and the frequency band is narrow. In addition, the 45-degree phase shifter using a frequency divider requires an input signal having a frequency four times the required local oscillation frequency, resulting in a problem that the power consumption of the frequency divider and the local oscillator increases.

  The present invention has been made to solve such problems, and an object of the present invention is to provide a 45-degree phase shifter capable of wideband and low power consumption.

  In order to solve the above-mentioned problem, according to claim 1 of the present invention, the first input signal is first inverted after the polarity is inverted by the clock input terminal of the first D flip-flop and the polarity inverting means, for example, an inverter circuit. Input to the clock input terminal of the second D flip-flop, the non-inverted output of the first D flip-flop is connected to the D input of the second D flip-flop, and the first input signal Output as a phase 0 degree output signal, and the polarity inversion output of the first D flip-flop is output as a phase 180 degree output signal with respect to the first input signal, and the second D flip-flop The non-inverted output of is input to the D input of the first D flip-flop and is output as an output signal having a phase of 90 degrees with respect to the first input signal. The D flip-flop of the second D flip-flop has a first ½ frequency divider configured to be output as an output signal of 270 degrees with respect to the first input signal. The output signal of the phase 0 degree of the frequency divider is a clock input terminal of the second 1/2 frequency divider having the same configuration as the first 1/2 frequency divider, and one input terminal of the first mixer. And a first input terminal of the third mixer as a second input signal, and the output signal of the phase 90 degrees of the first 1/2 divider is the first 1/2 divider. Is input as a third input signal to a clock input terminal of a third ½ divider having the same configuration as the frequency divider, and the output signal of the phase 270 degrees of the first ½ divider is a second input signal. Input to one input terminal of the mixer and one input terminal of the fourth mixer, respectively. One input terminal of the second half frequency divider receives an output having a phase of 0 degree with respect to the second input signal of the second half frequency divider. An output signal having a phase of 90 degrees with respect to the input signal is input to the other input terminal of the second mixer, and a phase 45 with respect to the third input signal of the third 1/2 divider. Is output to the other input terminal of the third mixer, and the output signal having a phase of 135 degrees with respect to the input signal of the third ½ divider is the output of the fourth mixer. The first input signal is added to the other input terminal, and the output of the first mixer and the output of the second mixer are added by a first adder, so that the phase of the first input signal is 0 degrees. The output signal of the third mixer and the output of the fourth mixer are added by the second adder, A configuration for forming an output signal having a phase of 45 degrees with respect to the first input signal is defined.

According to a second aspect of the present invention, in the wideband 45-degree phase shifter according to the first aspect, the first positive-phase and the negative-phase input terminals are respectively connected to the positive-phase and negative-phase input terminals of the first ½ divider. Input signal of the first 1/2 divider, the output signal of phase 0 degree is the positive phase input terminal of the second 1/2 divider, and the first mixer Of the first mixer and the output signal of the phase 180 degrees of the first ½ divider is the second ½ divider. Input to the negative phase input of the frequency divider, one input terminal of the fifth mixer, and one input terminal of the seventh mixer, and the phase of 90 degrees of the first 1/2 frequency divider The output signal includes the positive phase input terminal of the third 1/2 divider, one input terminal of the sixth mixer, and one input terminal of the eighth mixer. The phase 270 degree output signal of the first 1/2 divider is input to the negative phase input terminal of the third 1/2 divider and one input of the second mixer. Terminal and one input terminal of the fourth mixer,
The phase 0 degree output signal of the second 1/2 divider is input to the other input terminal of the first mixer, and the positive phase input signal of the second 1/2 divider. In contrast, an output signal having a phase of 180 degrees is input to the other input terminal of the fifth mixer,
The 90-degree output signal of the second 1/2 divider is input to the other input terminal of the second mixer, and the positive-phase input signal of the second 1/2 divider. The output signal having a phase of 270 degrees is input to the other input terminal of the sixth mixer, and the output signal having the phase of 45 degrees of the third 1/2 divider is the third mixer. An output signal having a phase of 225 degrees with respect to the positive phase input signal of the third 1/2 divider is input to the other input terminal of the seventh mixer. And
The output signal of the phase of 135 degrees of the third 1/2 divider is input to the other input terminal of the fourth mixer, and the positive phase input signal of the third 1/2 divider Is output to the other input terminal of the eighth mixer, and the output of each of the first, second, fifth and sixth mixers is the first addition. Are added to the output unit to form the output signals of the positive phase and the reverse phase of 0 phase with respect to the first input signal, and the outputs of the third, fourth, seventh and eighth mixers Stipulates a configuration in which the signals are input to the second adder and added to form the output signals of the positive phase and the negative phase having a phase of 45 degrees with respect to the first input signal.

  In Claim 3, In the wideband 45 degree phase shifter of Claim 1 or Claim 2, Each said output terminal of the said 2nd and 3rd 1/2 frequency divider, The input terminal of each said mixer, A low-pass filter is provided between them to suppress harmonic components contained in the output signal of the ½ frequency divider and then input to the mixers.

  As described above, according to the present invention, a phase difference of 45 degrees is given by a frequency division operation and a multiplication operation instead of giving a phase difference by a resistance element or a capacitor, so that it is possible to operate in a wide band. . In addition, since the input frequency to the frequency divider can be lowered to 4/3 times the required local oscillation frequency, the power consumption of the frequency divider and the local oscillator can be reduced.

(Example 1)
FIG. 1 is a circuit diagram showing a configuration of a 45 degree phase shifter according to a first embodiment of the present invention. In FIG. 1, 1 is a first 1/2 divider, 2 is a second 1/2 divider, 3 is a third 1/2 divider, and each 1/2 divider is shown in FIG. 6 is configured to generate output signals having four types of phases with respect to the input signal shown in FIG. Further, 4 is a first mixer, 6 is a second mixer, 8 is a third mixer, 10 is a fourth mixer, 12 is a first adder, and 13 is a second adder. FIG. 2 is a timing chart showing the operation of the circuit of FIG. 1 according to the first embodiment.

A signal input from the input terminal V _in is (referred to as the clock input terminal below for a clock input terminal of the D flip-flop.) The first 1/2 frequency divider 1 to the data input terminal is input to the C _p, the signal An output signal in which the logic output high or low polarity is inverted is output from the output terminal V _{0 of the} first ½ divider 1 at every falling edge. The output signal obtained by inverting the high or low logic output at every rising edge of the input terminal V _in from input signal is output from the first output terminal V ₉₀ 1/2 frequency divider 1. An inverted output of the signal output from the output terminal V ₀ is output from the output terminal V ₁₈₀ , and an inverted output of the signal output from the output terminal V ₉₀ is output from the output terminal V ₂₇₀ , respectively.
Therefore when the duty ratio of the input from the input terminal _{V in} signal is 50%, terminal _{V 0,} V _90, V _{180, V 270} respectively 0 degrees is the phase of the signal is output from, 90, 180, 270 every time, the frequency of these output signals is 1/2 of the signal both inputted from the input terminal V _in.

The signal output from the output terminal V _{0 of} the first ½ divider 1 is input to the clock input terminal C _p ′ of the second ½ divider 2 as a second input signal. An output signal obtained by inverting high or low of the logic output is output from the output terminal V ₀ ′ of the second 1/2 divider 2 at every falling edge of the input signal 2. The signal output from the output terminal V _{90 of} the first 1/2 divider 1 is input to the clock input terminal C _p ″ of the third 1/2 divider 3 as a third input signal, At every falling edge of the third input signal, an output signal obtained by inverting the logic output high or low is output from the output terminal V ₄₅ ′ of the third 1/2 frequency divider 3. Signal output from the output terminal V _{0 'and} the output terminal V _45' is 1/4 of the frequency of both signals input from the input terminal V _in. The A signal output _'signal and an output terminal V ₄₅ output from _the' from the output terminal V _0, 1/4 of the frequency of the signal to the input signal frequency of the input terminal V _in, as shown in FIG. 2 The phase is shifted 45 degrees.

The output signal obtained by inverting the logic output high or low at every rising edge of the second input signal input to the clock input terminal C _p ′ of the second ½ divider 2 is the second ½. It is output from the terminal V ₉₀ ′ of the frequency divider 2. Further, the inverted output of the signal output from the output terminal V ₀ ′ is output to the output terminal V ₁₈₀ ′, and the inverted output of the signal output from the output terminal V ₉₀ ′ is output to the output terminal V ₂₇₀ ′. On the other hand, an output signal obtained by inverting the logic output high or low at every rising edge of the third input signal input to the clock input terminal C _p ″ of the third ½ divider 3 is the third 1 / 2 is output from the output terminal V ₁₃₅ ′ of the frequency divider 3. Further, an inverted output of the signal output from the output terminal V ₄₅ ′ is output to the output terminal V ₂₂₅ ′, and an inverted output of the signal output from the output terminal V ₄₅ ′ is output to the output terminal V ₃₁₅ ′.
Therefore when the duty ratio of the input from the input terminal _{V in} signal is 50%, the output terminal _{V 0 ', V 90',} V 180 ', V 270', V 45 ', V 135', V 225 ', V each 0 ° to the phase of the signal is output from the ₃₁₅ ', 90, 180, 270 degrees, 45 degrees, 135 degrees, 225 degrees, it is 315 degrees, the input from the input terminal _{V in} any frequency of the output signal 1/4 of the generated signal.
The output signal of the second ½ divider 2 or the third ½ divider 3 and the output of the first ½ divider 1 are multiplied by a mixer and up-converted.

  Each output of the 1/2 divider is in principle a rectangular wave as shown in FIG. When the rectangular wave is viewed as a frequency component, it is represented by the sum of a fundamental wave component and odd-order harmonic components such as third harmonic and fifth harmonic. When each 1/2 frequency divider output is in the microwave band, the 3rd harmonic is higher than the frequency of the frequency divider, so it is not output much. Mainly the fundamental wave component is output and close to a sine wave. Often has a waveform.

Therefore, it is assumed that only the fundamental wave component of the 1/2 divider output is handled and expressed as a sine wave. If the signal output from the output terminal V _{0 of} the first 1/2 divider 1 is cos ω ₁ t, the signal output from the output terminal V _{270 of the} first 1/2 divider 1 is cos ( ω ₁ t + 270 °). If the signal output from the output terminal V ₀ ′ of the second ½ divider 2 is cos ω ₂ t, the signal output from the output terminal V ₉₀ ′ of the second ½ divider 2 Is cos (ω ₂ t + 90 °), the signal output from the output terminal V ₄₅ ′ of the third ½ divider 3 is cos (ω ₂ t + 45 °), and the third ½ divider 3 A signal output from the output terminal V ₁₃₅ ′ can be written as cos (ω ₂ t + 135 °).
The signal output from the output terminal V _{0 of} the first ½ divider 1 and the signal output from the terminal V ₀ ′ of the second ½ divider 2 are input to the first mixer 4. As a result, the output signal of the first mixer 4 is as follows.
cosω ₁ t ・ cosω ₂ t = (1/2) cos (ω ₁ + ω ₂ ) t + (1/2) cos (ω ₁ -ω ₂ ) t (Equation 1)
The first term on the right side is an up-conversion output that is a desired wave, and the second term is an image signal.
The signal output from the output terminal V _{270 of} the first 1/2 divider 1 and the signal output from the output terminal V ₉₀ ′ of the second 1/2 divider 2 are supplied to the second mixer 6. When input and multiplied, the output signal of the second mixer 6 is as follows.
cos (ω ₁ t + 270 °) ・ cos (ω ₂ t + 90 °)
= (1/2) cos {(ω ₁ + ω ₂ ) t + (270 ° + 90 °)} + (1/2) cos {(ω ₁ -ω ₂ ) t + (270 ° -90 °)}
= (1/2) cos {(ω ₁ + ω ₂ ) t + 360 °} + (1/2) cos {(ω ₁ -ω ₂ ) t + 180 °}
= (1/2) cos (ω ₁ + ω ₂ ) t- (1/2) cos (ω ₁ -ω ₂ ) t (Equation 2)
Therefore, the first adder 12 adds the output signal of the first mixer 4 expressed by the formula (1) and the output signal of the second mixer 6 expressed by the formula (2). , The component of cos (ω ₁ −ω ₂ ) t that is an image signal is canceled, and only the component of cos (ω ₁ + ω ₂ ) t that is an up-converted output is output from the first adder 12 to the output terminal V _out0 . Is done.
The signal output from the output terminal V _{0 of} the first 1/2 divider 1 and the signal output from the terminal V ₄₅ ′ of the third 1/2 divider 3 are supplied to the third mixer 8. When input and multiplied, the output signal of the third mixer 8 is as follows.
cosω ₁ t ・ cos (ω ₂ t + 45 °)
= (1/2) cos {(ω ₁ + ω ₂ ) t + 45 °} + (1/2) cos {(ω ₁ -ω ₂ ) t-45 °} (Equation 3)
The signal output from the output terminal V _{270 of} the first 1/2 divider 1 and the signal output from the output terminal V ₁₃₅ ′ of the third 1/2 divider 3 are supplied to the fourth mixer 10. When input and multiplied, the output signal of the fourth mixer 10 is as follows.
cos (ω ₁ t + 270 °) ・ cos (ω ₂ t + 135 °)
= (1/2) cos {(ω ₁ + ω ₂ ) t + (270 ° + 135 °)} + (1/2) cos {(ω ₁ -ω ₂ ) t + (270 ° -135 °)}
= (1/2) cos {(ω ₁ + ω ₂ ) t + 360 ° + 45 °} + (1/2) cos {(ω ₁ -ω ₂ ) t + 180 ° -45 °}
= (1/2) cos {(ω ₁ + ω ₂ ) t + 45 °}-(1/2) cos {(ω ₁ -ω ₂ ) t-45 °} (Equation 4)
Therefore, by adding the output signal of the third mixer 8 expressed by the equation (3) and the output signal of the fourth mixer 10 expressed by the equation (4) by the second adder 13, The component of cos {(ω ₁ −ω ₂ ) t−45 °} that is an image signal is canceled, and only the component of cos {(ω ₁ + ω ₂ ) t + 45 °} that is an up-converted output is the second adder 14. To the output terminal V _out45 .

Phase of the signal is output to the output terminal _{V out45 cos {(ω 1 +} ω 2) t + 45 °} are offset by a phase 45 degrees of a signal is output to the output terminal _{V out0 cos (ω 1 + ω} 2), It can be seen that it is operating as a 45 degree phase shifter.
In this configuration, a phase difference is not given by a resistance element or a capacitor, but only a frequency division operation and a multiplication operation are performed, and the circuit operates in a wide band without being affected by the frequency characteristics of these passive components.

Further, when the frequency of the signal output from the first adder 12 and the second adder 13 is f, the frequency of the signal input from the input terminal V _in may be the (4/3) f. That is, the output frequency of the first 1/2 divider 1 is (2/3) f, and the output frequencies of the second 1/2 divider 2 and the third 1/2 divider 3 are (1 / 3) The signal of frequency f is obtained by multiplying the output of the first 1/2 divider 1 by the output of the second 1/2 divider 2 or the third 1/2 divider 3. Have gained. Therefore, the input frequency to the first 1/2 frequency divider 1 is 4/3 times the required local oscillation frequency, which is much lower than the conventional 4 times. For example, when a local oscillation frequency of 3 GHz is required, the input frequency to the frequency divider is 4 GHz, which is much lower than the conventional 12 GHz. Therefore, the power consumption of the frequency divider and the local oscillator can be reduced.

The phase relationship of the signal input to the mixer is not limited to the above. For example, the input to the second mixer 6 is the output signal of the output terminal V ₉₀ of the first 1/2 divider 1 and the output signal of the output terminal V ₂₇₀ ′ of the second 1/2 divider 2. However, the component of the image signal is canceled, and only the component of the up-conversion output is output from the first adder 12 to the output terminal _Vout0 . That is, it is sufficient if the sum of the phases of the two input signals to the second mixer 6 is an integral multiple of 360 degrees and the phase difference between the two input signals is an odd multiple of 180 degrees. Similarly, the input to the fourth mixer 10 is the output signal of the output terminal V ₉₀ of the first 1/2 divider 1 and the output signal of the output terminal V ₃₁₅ ′ of the second 1/2 divider 2. However, the component of the image signal is canceled, and only the component of the up-conversion output is output from the second adder 13 to the output terminal V _out45 . That is, the sum of the phases of the two input signals to the fourth mixer 10 is obtained by adding or subtracting an integral multiple of 360 degrees to 45 degrees, or the phase difference of the two input signals is added an odd multiple of 180 degrees to 45 degrees or Any subtraction may be used.

When the 1/2 divider output is close to a square wave and contains many harmonic components, the fundamental component and the harmonic component or the frequency component obtained by multiplying the harmonic components by the mixer is the desired local oscillation frequency. It becomes spurious for the component of. Therefore, in this case, a low-pass filter may be provided at the output of each 1/2 divider to suppress harmonic components. Moreover, it is good also as a structure which removes a spurious by inputting the output of each mixer into a band pass filter.
(Example 2)
FIG. 3 is a circuit diagram showing a configuration of a 45 degree phase shifter according to the second embodiment of the present invention. The same parts as those in FIG. 1 are given the same numbers. Reference numeral 5 denotes a fifth mixer, 7 denotes a sixth mixer, 9 denotes a seventh mixer, and 11 denotes an eighth mixer. The isolation between the input terminal and output terminal of each mixer is not infinite, and there is a leakage component. In this embodiment, the leakage component is canceled by preparing a mixer for inputting a signal whose phase is shifted by 180 degrees. That is outputted from the output terminal _{V 0} which first 1/2 frequency divider 1, with respect to the first mixer 4 the signal cos .omega ₁ inputted to t, the signal of the phase inverted _{cos (ω 1 t + 180 °} ) Is output from the output terminal V ₁₈₀ of the first ½ divider 1 and input to the fifth mixer 5. Thus for the component input signal cos .omega ₁ t of the first mixer 4 from leaking to the output terminal, it is canceled by the component input signal cos of the fifth mixer _{5 (ω 1 t + 180 °} ) from leaking to the output terminal. Similarly the output from the second 1/2 frequency divider 2 terminal _{V 0} ', with respect to the first mixer 4 the signal is input to the cos .omega ₂ t, the signal of the opposite phase cos (ω ₂ t + 180 ° ) Is output from the terminal V ₁₈₀ ′ of the second ½ divider 2 and input to the fifth mixer 5. Thus for the component input signal cos .omega ₂ t of the first mixer 4 from leaking to the output terminal, it is canceled by the component input signal cos of the fifth mixer _{5 (ω 2 t + 180 °} ) from leaking to the output terminal. Further, an output signal obtained by multiplying the second input signal of the fifth mixer 5 is expressed by the following equation.
cos (ω ₁ t + 180 °) ・ cos (ω ₂ t + 180 °)
= (1/2) cos {(ω ₁ + ω ₂ ) t + (180 ° + 180 °)} + (1/2) cos {(ω ₁ -ω ₂ ) t + (180 ° -180 °)}
= (1/2) cos {(ω ₁ + ω ₂ ) t + 360 °} + (1/2) cos (ω ₁ -ω ₂ ) t
= (1/2) cos (ω ₁ + ω ₂ ) t + (1/2) cos (ω ₁ -ω ₂ ) t (Equation 5)
Therefore, it is in phase with the equation (1), which is the output signal of the first mixer 4, and is added together by the first adder 12 to strengthen each other.

  Similarly, two signals obtained by inverting two input signals to the second mixer 6 are input to the sixth mixer 7, and two signals obtained by inverting both the two input signals to the third mixer 8 are the second signals. 7 input to the mixer 9 and the two signals obtained by making the two input signals to the fourth mixer 10 opposite in phase are input to the eighth mixer 11 to cancel the leakage component and multiply the two input signals. Strengthen the output signal.

As in the first embodiment, the phase of the signal output from the second adder 13 to the output terminal _Vout45 is 45 degrees with the phase of the signal output from the first adder 12 to the output terminal _Vout0. It is only shifted and operates as a 45-degree phase shifter as a whole.

  In FIG. 3, the input to the frequency divider is a differential input that inputs two signals of opposite phase, and the output of the adder is a differential output that outputs two signals of opposite phase, and only one signal is input. Compared to the single-ended input / output that outputs, the noise can be reduced. Operation with single-ended input / output is also possible.

A single mixer and a mixer to which two signals, the two input signals of which have opposite phases, are input can be integrated by using a double balance mixer. Therefore, the first mixer 4 and the fifth mixer 5, the second mixer 6 and the sixth mixer 7, the third mixer 8 and the seventh mixer 9, the fourth mixer 10 and the eighth mixer 11 are respectively It is possible to make one double balance mixer.
Both the first embodiment and the second embodiment can be easily integrated using transistors, and can be configured as an integrated IC.

The circuit diagram which shows the structure of the 45 degree | times phase shifter which is a 1st Example. The timing diagram which shows the operation | movement in a 1st Example. The circuit diagram which shows the structure of the 45 degree | times phase shifter which is a 2nd Example. A circuit diagram of a quadrature demodulator using an even harmonic mixer. A circuit diagram showing a quadrature modulator using an even harmonic mixer. The circuit diagram which shows the 90 degree phase shifter using the conventional 1/2 frequency divider. The timing diagram which shows operation | movement of the 90 degree phase shifter using the conventional 1/2 frequency divider.

Explanation of symbols

1, 2, 3: 1/2 frequency divider 4, 5, 6, 7, 8, 9, 10, 11, 55, 56, 75, 76: mixer 12, 13: adders 51, 72, 73: input Terminals 52, 53, 71: Output terminals 58, 78: 45 ° phase shifters 59, 60, 79, 80: Low-pass filter 100, 101: D flip-flop 102: Inverter circuit

Claims (3)

The first input signal is input to the clock input terminal of the first D flip-flop and the clock input terminal of the second D flip-flop after the polarity is inverted by the polarity inverting means,
The polarity non-inverted output of the first D flip-flop is connected to the D input of the second D flip-flop, and is output as an output signal having a phase of 0 degrees with respect to the first input signal.
The polarity inversion output of the first D flip-flop is output as an output signal having a phase of 180 degrees with respect to the first input signal.
The non-inverting output of the polarity of the second D flip-flop is input to the D input of the first D flip-flop, and is output as an output signal having a phase of 90 degrees with respect to the first input signal.
A polarity inverting output of the second D flip-flop has a first ½ divider configured to be output as an output signal of 270 degrees with respect to the first input signal,
The output signal of the phase 0 degree of the first 1/2 divider is a clock input terminal of a second 1/2 divider having the same configuration as the first 1/2 divider, Are input as a second input signal to one input terminal of the mixer and one input terminal of the third mixer,
The 90-degree output signal of the first 1/2 divider is supplied to the clock input terminal of the third 1/2 divider having the same configuration as that of the first 1/2 divider. Input as an input signal,
The output signal of the phase 270 degrees of the first 1/2 divider is input to one input terminal of the second mixer and one input terminal of the fourth mixer, respectively.
The other one input terminal of the first mixer receives an output of phase 0 degree with respect to the second input signal of the second ½ divider,
An output signal having a phase of 90 degrees with respect to the second input signal of the second 1/2 divider is input to the other input terminal of the second mixer,
An output signal having a phase of 45 degrees with respect to the third input signal of the third 1/2 divider is input to the other input terminal of the third mixer,
An output signal having a phase of 135 degrees with respect to the input signal of the third ½ divider is input to the other input terminal of the fourth mixer,
The output of the first mixer and the output of the second mixer are added by a first adder to form an output signal having a phase of 0 degrees with respect to the first input signal,
An output signal having a phase of 45 degrees with respect to the first input signal is formed by adding the output of the third mixer and the output of the fourth mixer by a second adder. Broadband 45 degree phase shifter. The broadband 45 degree phase shifter according to claim 1,
The phase 0 degree output signal of the first 1/2 divider is the positive phase input terminal of the second 1/2 divider, one input terminal of the first mixer, Input to one input terminal of the third mixer,
The 180-degree output signal of the first 1/2 divider is connected to the negative phase input of the second 1/2 divider, one input terminal of the fifth mixer, Input to one of the input terminals of the mixer
The output signal of the phase 90 degrees of the first 1/2 divider is the positive phase input terminal of the third 1/2 divider, one input terminal of the sixth mixer, Is input to one input terminal of 8 mixers,
The output signal of the phase 270 degrees of the first 1/2 divider is the reverse-phase input terminal of the third 1/2 divider, one input terminal of the second mixer, Input to one input terminal of the fourth mixer,
The phase 0 degree output signal of the second 1/2 divider is input to the other input terminal of the first mixer,
An output signal having a phase of 180 degrees with respect to the positive phase input signal of the second 1/2 divider is input to the other input terminal of the fifth mixer,
The 90-degree output signal of the second 1/2 divider is input to the other input terminal of the second mixer,
An output signal having a phase of 270 degrees with respect to the positive phase input signal of the second ½ divider is input to the other input terminal of the sixth mixer,
The output signal of 45 degrees of the third 1/2 divider is input to the other input terminal of the third mixer,
An output signal having a phase of 225 degrees with respect to the positive phase input signal of the third 1/2 divider is input to the other input terminal of the seventh mixer,
The output signal of the phase of 135 degrees of the third 1/2 divider is input to the other input terminal of the fourth mixer,
An output signal having a phase of 315 degrees with respect to the positive phase input signal of the third 1/2 divider is input to the other input terminal of the eighth mixer,
The outputs of the first, second, fifth, and sixth mixers are input to and added to a first adder, and the outputs of the positive phase and the negative phase having a phase of 0 degree with respect to the first input signal are added. Form a signal,
The outputs of the third, fourth, seventh and eighth mixers are input to and added to a second adder, and outputs of positive and negative phases of 45 degrees with respect to the first input signal. A wideband 45 degree phase shifter characterized by forming a signal. The broadband 45 degree phase shifter according to claim 1 or 2,
Harmonics included in the output signal of the 1/2 divider by providing a low pass filter between the output terminals of the second and third 1/2 dividers and the input terminals of the mixers. A broadband 45-degree phase shifter, wherein components are suppressed and then input to the mixers.

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