JP2006270307A - Double conversion receiver and semiconductor integrated circuit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a double conversion receiver capable of avoiding reception sensitivity deterioration and sufficiently ensuring an anti-disturbing wave characteristic. <P>SOLUTION: The receiver adopts a configuration wherein either of local frequencies of first and second frequency converters 102, 104 is selected to be a lower local frequency and the other is selected to be a higher local frequency, and the suppressing amount in the anti-disturbing wave characteristic is determined by a sum of a suppression amount at a lower frequency side by a first filter 103 and a suppression amount at a higher frequency side by a second filter 105, or a sum of a suppression amount at a higher frequency side by the first filter 103 and a suppression amount at a lower frequency side by the second filter 105. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a double conversion receiver, and more particularly to a receiving circuit in which an intermediate frequency filter is integrated in a semiconductor.

  In recent years, higher integration of communication semiconductor integrated circuits has progressed, and semiconductor integration of intermediate frequency filters, which have conventionally been configured with external passive components, has progressed.

  FIG. 7 is a block diagram showing the configuration of a conventional double conversion receiver, in which both the first frequency converter 102 and the second frequency converter 104 are upper local or lower local. Is used, and the sum of the suppression amounts on the high frequency side of the first filter 103 and the second filter 105 ensures the order of the filter that satisfies the suppression amount that satisfies the radio communication interference standard. In the figure, reference numeral 101 denotes an input unit.

  FIGS. 8A to 8E are diagrams for explaining the suppression characteristics of the filter according to the conventional configuration. FIG. 8A shows the suppression characteristics of the first filter 103, and FIG. The suppression characteristic of the filter 105 is shown.

  Here, when the local frequency LO1 of the first frequency converter 102 and the local frequency LO2 of the second frequency converter 104 are both lower local, the relationship between the frequency of the input signal and the center frequency of the filter. The relationship is equal, and FIG. 8A and FIG. 8C and FIG. 8B and FIG. 8D are the same. Therefore, the total suppression amount of the first filter 103 and the second filter 105 is as shown in FIG. 8E, and the suppression amount on the high frequency side is smaller than the suppression amount on the lower frequency side than the center frequency. By increasing the filter order of the first filter 103 and the second filter 105 and increasing the suppression amount of the solid line in FIG. 8A to FIG. 8E to the suppression characteristic of the dotted line, the radio interference standard is satisfied. Only used to ensure the suppression characteristics.

  The relationship between frequency and signal level in the conventional double conversion receiver will be described with reference to FIG.

  First, it is assumed that a desired wave: C, an interference wave having a frequency lower than the desired wave: Ilow, and an interference wave: IHigh having a frequency higher than the desired wave: IHigh are input to the input unit 101 as input frequencies. These input signals are CIF1 as an intermediate frequency 1, IlowIF1 as an intermediate frequency 1 of an interfering wave Ilow, and IHighIF1 as an intermediate frequency 1 of an interfering wave IHigh depending on the difference from the local frequency LO1 of the first frequency converter 102. Is output. The frequency relationship of this frequency 1 is similar to the relationship of the input frequency. The intermediate frequency 1: IHighIF1 of the interference wave higher than the desired wave is higher than the intermediate frequency 1: CIF1 of the desired wave, and the interference wave lower than the desired wave. Intermediate frequency 1: IlowIF1 is lower.

  By passing through the first filter 103, these intermediate frequency 1 signals pass through the intermediate frequency 1: CIF1 of the desired wave without being suppressed, and the intermediate frequency 1: IHighIF1 of the interfering wave higher than the desired wave is first. The intermediate frequency 1: IlowIF1 of the interference wave lower than the desired wave is attenuated by the amount of attenuation on the low frequency side of the first filter, and is attenuated by the amount of suppression on the high frequency side of the first filter 103. It passes through the filter 103 (provided that there is no passage loss of the first filter).

  Here, since the suppression amount of the first filter 103 is larger on the low frequency side than on the high frequency side, assuming that the input level of the interference wave entering the input unit 101 is Ilow = IHigh, the first filter 103 The signal level after passing through 103 has a relationship of IlowIF1 <IHighIF1. Furthermore, the signal that has passed through the first filter 103 is output as an intermediate frequency 2 due to the difference from LO2 of the second frequency converter 104. The output signal of the intermediate frequency 2 is output as the intermediate frequency 2 of the desired wave, CIF2, IlowIF2 as the output signal of the interference wave Ilow, and the output signal of the interference wave IHigh is output as IHighIF2.

  This frequency relationship is also the same as the relationship of the input frequency. The intermediate frequency 2 of the interference wave higher than the desired wave 2: IHighIF2 is higher than the intermediate frequency 1: CIF2 of the desired wave, and the intermediate frequency 2 of the interference wave lower than the desired wave. : IlowIF2 is lower, where these intermediate frequency 2 signals pass through the second filter 105, so that the intermediate frequency 2: CIF2 of the desired wave passes through without being suppressed and is higher than the desired wave Interfering wave intermediate frequency 2: IHighIF2 is attenuated by the amount of suppression on the high frequency side of second filter 105, and interfering wave intermediate frequency 2: IlowIF2 lower than the desired wave is attenuated on the low frequency side of the first filter. It attenuates by the amount and passes through the second filter 105 (provided that there is no passing loss of the second filter).

Here, since the suppression amount of the second filter 105 is larger on the low frequency side than on the high frequency side, if the input level of the interference wave that has entered the input is Ilow = IHigh, The signal level after passing has a relationship of IlowIF2 << IHighIF2, and the suppression amount of the filter is excessive in order to suppress the interference wave on the high frequency side.
BEHZAD RAZAVI "RF MICROELECTRONICS" published by Prentice 1998 published pages 157-158

  However, the filter assembled in the conventional semiconductor integrated circuit has a problem that, by increasing the order, the circuit scale increases, NF is increased, and reception sensitivity is deteriorated.

  An object of the present invention is to solve the above-mentioned conventional problems, to provide a double conversion receiver capable of reducing the order of a filter and improving NF, and a semiconductor integrated circuit used for the double conversion receiver. To do.

  In order to achieve the object, the invention according to claim 1 is a first frequency converter for frequency converting an input signal, and has a predetermined frequency band, and the first frequency converter. A first filter that passes a frequency converted signal from the first frequency converter, a second frequency converter for frequency converting the signal from the first filter, and the second frequency converter having a predetermined frequency band A second filter that allows a frequency signal from the filter to pass through, wherein one of the first frequency converter and the second frequency converter is configured as a lower local, and the other is configured as an upper local, A filter in which at least one of the one filter and the second filter is integrated is used.

  According to a second aspect of the present invention, in the double conversion receiver according to the first aspect, the interference wave suppression on the high frequency side with respect to the input signal is the suppression amount on the high frequency side of the first filter and the second filter. Of the low frequency side of the first filter, the suppression amount of the low frequency side of the first filter and the suppression amount of the high frequency side of the second filter When the interference signal suppression on the high frequency side with respect to the input signal is determined by the sum of the suppression amount on the low frequency side of the first filter and the suppression amount on the high frequency side of the second filter The low frequency side interference wave suppression is determined by the sum of the high frequency side suppression amount of the first filter and the low frequency side suppression amount of the second filter.

  Invention of Claim 3 is a semiconductor integrated circuit used for the double conversion receiver of Claim 1, Comprising: Said 1st frequency converter, said 2nd frequency converter, and said 1st filter And at least one of the second filter and an integrated circuit.

  As described above, the double conversion receiver according to the present invention is configured so that the local frequency of the first frequency converter and the second frequency converter is one lower local and the other is upper local, The sum of the suppression amount on the high frequency side and the suppression amount on the low frequency side of the second filter, or the sum of the suppression amount on the low frequency side of the first filter and the suppression amount on the high frequency side of the second filter If the suppression amount satisfies the wireless communication interference standard, the filter order can be minimized, the circuit scale can be reduced, and the NF can be reduced. Can be prevented.

  According to the double conversion receiver and the semiconductor integrated circuit of the present invention, it is possible to configure the filter with the minimum order, and it is possible to reduce the circuit scale and prevent the reception sensitivity from deteriorating.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a double conversion receiver for explaining the first embodiment of the present invention.

  In FIG. 1, a first frequency converter 102, a first filter 103, a second frequency converter 104, and a second filter 105 are connected in series, and the first filter 103 or the second filter 105 At least one is constituted by a semiconductor integrated circuit, and the first filter 103 and the second filter 105 each have a predetermined frequency band. In the figure, reference numeral 101 denotes an input unit.

  When the local frequency used for the first frequency converter 102 is lower local (input frequency: fRF = local 1 frequency: fLO1 + intermediate frequency 1: fIF1), the local frequency used for the second frequency converter 104 Is upper local (intermediate frequency 1: fIF1 = local 2 frequency: fLO2−intermediate frequency 2: fIF2), or the local frequency used for the first frequency converter 102 is upper local (input frequency: fRF = local 1). In the case of frequency: fLO1−intermediate frequency 1: fIF1), the local frequency used for the second frequency converter 104 is lower local (intermediate frequency 1: fIF1 = local 2 frequency: fLO2 + intermediate frequency 2: fIF2). There is. That is, there is an upper / lower relationship between the local frequency 1 and the local frequency 2.

  As an example of this interrelationship, the local frequency 1: fLO1 is assumed to be lower local, and the local frequency 2: fLO2 is assumed to be upper local, with reference to the frequency relationship from the input signal to the output signal in this embodiment shown in FIG. .

  First, as an input signal, a desired wave: C and an interference wave having a frequency lower than the desired wave: Ilow and an interference signal having a frequency higher than the desired wave: C are input to the input unit 101 in FIG. To do. These input signals are output as an intermediate frequency 1 due to the difference from the local signal LO1 of the first frequency converter 102 (here, the frequency characteristics of the first frequency converter 102 are ignored). As for the output signal of the intermediate frequency 1, CIF1 is output as the intermediate frequency 1 of the desired wave, IlowIF1 is output as the intermediate frequency 1 of the interference wave Ilow, and IHighIF1 is output as the intermediate frequency 1 of the interference wave IHigh.

  The frequency relationship of the intermediate frequency 1 is the same as the relationship of the input signal frequency, but the intermediate frequency 1: IHighIF1 of the interference wave higher than the desired wave is higher than the intermediate frequency 1: CIF1 of the desired wave, and is lower than the interference of the desired wave. Wave intermediate frequency 1: IlowIF1 is lower. Here, these intermediate frequency 1 signals pass through the first filter 103, so that the intermediate frequency 1: CIF1 of the desired wave passes through without being suppressed, and the intermediate frequency 1: interfering wave higher than the desired wave 1: IHighIF1 is attenuated by the amount of suppression on the high frequency side of the first filter 103, and the intermediate frequency 1: IlowIF1 of the interference wave lower than the desired wave is attenuated by the amount of suppression on the low frequency side of the first filter 103. Then, it passes through the first filter 103 (provided that there is no passage loss of the first filter).

  Here, since the suppression amount of the first filter 103 is larger on the low frequency side than on the high frequency side, assuming that the input level of the interference wave entering the input unit 101 is Ilow = IHigh, the first filter 103. The signal level after passing has a relationship of IlowIF1 <IHighIF1. Further, the signal that has passed through the first filter 103 is output as an intermediate frequency 2 due to the difference from the local signal LO2 of the second frequency converter 104 (here, the frequency characteristic of the second frequency converter 104 is changed). Ignore). As the output signal of the intermediate frequency 2, CIF2 is output as the intermediate frequency 2 of the desired wave, IlowIF2 is output as the output signal of the interference wave Ilow, and IHighIF2 is output as the output signal of the interference wave IHigh.

  The frequency relationship of the intermediate frequency 2 is an inversion relationship with the relationship of the input signal frequency. The intermediate frequency 2: IHighIF2 of the interference wave higher than the desired wave is lower than the intermediate frequency 2: CIF2 of the desired wave, and the desired wave Lower interfering wave intermediate frequency 2: IlowIF2 is higher. Here, these intermediate frequency 2 signals pass through the second filter 105, so that the intermediate frequency 2: CIF2 of the desired wave passes through without being suppressed, and the intermediate frequency 2 of the disturbing wave higher than the desired wave. : IHighIF2 has a frequency lower than that of CIF2, attenuates by the amount of suppression on the low frequency side of the second filter 105, and the intermediate frequency 2 of the disturbing wave lower than the desired wave has a frequency lower than that of CIF2. It attenuates by the amount of suppression on the high frequency side of the second filter 105 and passes through the second filter 105 (provided that there is no passing loss of the second filter).

  Here, since the suppression amount of the second filter 105 is larger on the low frequency side than on the high frequency side, the interference wave: IHighIF2 can be attenuated more than the interference wave IlowIF2.

  As an example, the low frequency side suppression amount with respect to the center frequency of the first filter 103 and the second filter 105 is equal to the suppression amount on the high frequency side, and the low frequency side (−ΔHz) interference wave input to the input unit 101. : Ilow and high-frequency side (+ ΔHz) interference wave: If the input level of IHigh is equal, the interference wave of intermediate frequency 2: the output levels of IlowIF2 and IHighIF2 are equal.

  That is, as shown in the explanatory diagram of the suppression amount of the filter of the first embodiment shown in FIGS. 3A to 3E, the suppression amount of the first filter 103 in FIG. 3A is the first frequency converter. Since the local frequency of 102 is lower local, it becomes the suppression characteristic of FIG. 3C as it is, and the suppression amount of the second filter 105 of FIG. Because of the upper local, the frequency relationship is inverted, and the suppression characteristic shown in FIG. 3D is obtained. The suppression characteristic of the total filter from the input signal to the output signal is the low frequency side suppression as shown in FIG. The amount of suppression and the amount of suppression on the high frequency side are symmetric, the filter order can be minimized, the circuit scale can be reduced and NF can be reduced, and deterioration of reception sensitivity can be prevented. .

  Although the description of the local frequency 1: fLO1 and the upper local frequency 2: fLO2 as the lower local is omitted, the filter characteristics as shown in FIGS. 4A to 4E are obtained as a result.

  Since the order of the filters of the first filter 103 and the second filter 105 can be minimized, at least one of them can be integrated. Similarly, at least one of the first frequency converter 102 and the second frequency converter 104 can be integrated.

  FIG. 5 is a block diagram showing a configuration of a double conversion receiver according to the second embodiment of the present invention.

  In the second embodiment, a low noise amplifier (LNA) 100 is connected in series to the input signal unit of the first embodiment, the frequency converters 102 and 104 of the first embodiment are mixers (multipliers), and the second frequency converter 104 is used. A gain control amplifier (GCA) 106 is provided between the output of the second filter 105 and the second filter 105, and a field intensity detector (RSSI) 110 that controls the GCA 106, an output limiter (LIM) 107, and a PLL that generates the local signal LO1. (Phase Locked Loop) 1 (108), the configuration in the case of using the PLL2 that generates the local signal LO2 (109) is shown.

  In FIG. 5, a low noise amplifier (LNA) 100 is connected in series to the input unit 101. The LNA 100 may be configured as a single-stage amplifier or an amplifier connected in multiple stages, and the gain may be fixed or variable. The output of the LNA 100 is connected to the mixer input of the first frequency converter 102. Note that a filter that allows only necessary input frequency components to pass therethrough may be connected in series between the output of the LNA 100 and the first frequency converter 102.

  The first frequency converter 102 may have any configuration as long as it can output a desired intermediate frequency 1, and may be an image rejection mixer (IRM). Furthermore, the gain may be fixed or variable. A first filter 103 is connected in series to the output of the first frequency converter 102. The first filter 103 may have any order or configuration as long as it removes a band other than the desired frequency component of the intermediate frequency 1 (however, the interference wave other than the desired channel may be disturbed). Is required to satisfy the radio interference standard by the suppression amount of the first filter 103 and the second filter 105).

  Further, an amplifier may be included from the input to the output of the first filter 103, and the gain of this amplifier may be fixed or variable. The mixer input of the second frequency converter 104 is connected to the output of the first filter 103. The second frequency converter 104 may have any configuration as long as it can output a desired intermediate frequency 2 and may be an IRM. The gain may be fixed or variable.

  A variable gain amplifier 106 is connected in series to the output of the second frequency converter 104. The variable gain amplifier (GCA) 106 may have a fixed gain. The output of the GCA 106 is connected to the second filter 105 in series. The second filter 105 may have any order or configuration as long as it is configured to remove a band other than the desired frequency component of the intermediate frequency 2 (however, the interference wave other than the desired channel) Is required to satisfy the radio interference standard by the suppression amount of the first filter 103 and the second filter 105).

  Further, an amplifier may be included from the input to the output of the second filter 105, and the gain of this amplifier may be fixed or variable. A limiter amplifier (LIM) 107 is connected in series to the output of the second filter, and the output of the LIM 107 is connected to the output terminal. Any number of amplifier stages may be used as long as there is a gain sufficient to limit the LIM 107 input waveform.

  The PLL 1 (108) is a PLL that generates the local signal 1 (LO1) input to the first frequency converter 102, and is a frequency difference between the desired wave C of the input signal (RF) and the desired intermediate frequency 1. The LO1 frequency corresponding to is output. Note that the LO1 frequency is variable when the desired wave C frequency of the input signal (RF) changes, that is, when the channel is switched.

  The PLL 2 (109) is a PLL that generates the local signal 2 (LO 2) input to the second frequency converter 104, and corresponds to a frequency difference between the desired intermediate frequency 1 and the desired intermediate frequency 2. Outputs the LO2 frequency.

  The configuration in the second embodiment can be applied to any receiving system as long as it is a double conversion receiver. For example, PHS (Personal Handyphone System) or PDC (Personal Digital Cellular) Etc.

  Further, any one of the local of the first frequency converter 102 and the local of the second frequency converter 104 may be the upper local and the other may be the lower local.

  Here, the operation will be described for an example in which the local of the first frequency converter 102 is the lower local and the local of the second frequency converter 104 is only the upper local, and an example in which a PHS system is actually used.

  In FIG. 6, as a signal handled by the PHS, an input signal (RF) is 188.65 MHz to 1916.15 MHz, and a channel interval is 300 KHz. However, since the channel adjacent to the desired wave C is not used at the time of reception, the adjacent channel interference wave is the desired wave C ± 600 KHz, the adjacent channel interference wave characteristic standard> 50 dB at the PHS, the intermediate frequency 1 is 243.95 MHz, the intermediate Description will be made assuming that the frequency 2 is 1.2 MHz and the desired wave C = 1902.65 MHz.

  The input unit 101 has a desired wave C = 1902.65 MHz, an adjacent channel interference wave (desired wave C + 600 KHz) IHgh = 1903.25 MH, and (desired wave C-600 KHz) Ilow = 1902.05 MHz when 50 dB higher than the desired wave. Entered. These three input signals are amplified by the LNA 100 and frequency-converted by the mixer of the first frequency converter 102.

  At this time, the desired wave C is 1902.65 MHz, the frequency of the intermediate frequency 1 is 243.95 MHz, and the frequency of LO1 is lower than the frequency of the desired wave C minus the frequency of the intermediate frequency 1 because LO1 = 1658. It is set to 7 MHz.

Since the frequency component of the RF frequency ± LO1 frequency is output from the mixer by the mixer of the first frequency converter 102, the following six frequency components are output.
(1) IHigh + LO1 = 3561.95 MHz
(2) C + LO1 = 356.35 MHz
(3) Ilow + LO1 = 3560.75 MHz
(4) IHigh-LO1 = IHighIF1 = 244.55 MHz
(5) C + LO1 = CIF1 = 243.95 MHz
(6) Ilow + LO1 = IlowIF1 = 243.35 MHz
Among these six frequency components (1) to (6), the frequency components (1) to (3) are frequency components that are sufficiently separated from the pass band of the first filter 103. By passing through 103, the signal is attenuated to a level causing no problem in communication. Since the signal (5) is the same as the center frequency of the first filter 103, it is output without attenuation if there is no passing loss of the filter 103.

  Further, since the signal of (4) is attenuated by the suppression amount of +600 KHz of the first filter 103, if the specification is as shown in FIG. 6, the level of CIF1 is +50 dB-23 dB, and the above (6) Since the signal is attenuated by the amount of suppression of −600 KHz of the first filter 103, the CIF1 level becomes +50 dB−37 dB.

  Further, CIF1, IHighIF1, and IlowIF1 that are signals output from the first filter 103 are frequency-converted by the mixer of the second frequency converter 104. At this time, the CIF1 corresponding to the desired wave is 243.95 MHz, the frequency of the intermediate frequency 2 is 1.2 MHz, and the frequency of LO2 is LO2 = 245.15 MHz from the frequency of the CIF1−intermediate frequency 2 because it is upper local. Fixed to.

Since the mixer of the second frequency converter 104 outputs the frequency component of the IF1 frequency ± LO2 frequency from the mixer, the following six frequency components are output.
(7) IHighIF1 + LO2 = 489.7 MHz
(8) CIF1 + LO2 = 489.1MHz
(9) IlowIF1 + LO2 = 488.5Hz
(10) IHighIF1-LO2 = IHighIF2 = 600 KHz
(11) CIF1 + LO2 = CIF2 = 1.2 MHz
(12) IlowIF1 + LO2 = IlowIF2 = 1.8 MHz
The signals (7) to (12) of these six frequency components are amplified (or attenuated) by passing through the GCA 106. Note that the gain of the GCA 106 is variable by the electric field strength detector 110 (RSSI), and the variable characteristic may be linear or stepwise. In the case of stepwise, the strength of the input signal is increased. On the other hand, it may have a hysteresis characteristic. The node for detecting the electric field strength of RSSI may detect any signal from the input unit 101 to the output of 107, and a plurality of detection nodes may be provided.

  Among the signals (7) to (12) output from the GCA 106, the signals (7) to (9) are sufficiently separated from the pass band of the second filter 105, so that the level has no problem in communication. Attenuated. Since the signal of (11) is the same as the center frequency of the second filter 105, it is output without attenuation if there is no passing loss of the filter 105.

  Further, since the signal of (10) is attenuated by the amount of suppression of −600 KHz of the second filter 105, the specification shown in FIG. 6 results in a CIF2 level of +50 dB-23 dB-37 dB, and Since the signal of (12) is attenuated by the amount of suppression of +600 KHz of the second filter 105, the CIF2 level becomes +50 dB-37 dB-23 dB.

  Here, since the required signal-to-noise ratio (SNR)> 10 dB in the specification shown in FIG. 6, the level difference between the desired wave CIF2 input to the LIM 107 and the disturbing waves IHighIF2 and IlowIF2 is 10 dB or more. If so, the radio interference requirement specification can be satisfied.

  As described above, in this embodiment, it is possible to minimize the order of the intermediate frequency filter by alternately using the upper local and the lower local, and by reducing the circuit scale and accompanying NF improvement, It is possible to provide a double conversion receiver that can reduce deterioration in reception sensitivity.

  The present invention is applied to a double conversion receiver, and is particularly effective when used in a receiving circuit in which an intermediate frequency filter is integrated in a semiconductor.

The block diagram which shows the structure of the double conversion receiver for demonstrating Embodiment 1 of this invention. The figure which shows the relationship of the frequency versus signal level in this embodiment Explanatory drawing of the suppression characteristic of a filter when the local signal 1 (LO1) is lower local and the local signal 2 (LO2) is upper local in the first embodiment. Explanatory drawing of the suppression characteristic of a filter when the local signal 1 (LO1) is upper local and the local signal 2 (LO2) is lower local in the first embodiment. The block diagram which shows the structure of the double conversion receiver of Embodiment 2 of this invention. Explanatory drawing of various specifications in the second embodiment Block diagram showing the configuration of a conventional double conversion receiver Explanatory diagram of filter suppression characteristics in a conventional double conversion receiver The figure which shows the relationship of the frequency versus signal level in the conventional double conversion receiver

Explanation of symbols

100 Low noise amplifier (LNA)
DESCRIPTION OF SYMBOLS 101 Input part 102 1st frequency converter 103 1st filter 104 2nd frequency converter 105 2nd filter 106 Gain control amplifier (GCA)
107 Output limiter (LIM)
108,109 PLL
110 Field strength detector (RSSI)

Claims (3)

  A first frequency converter for frequency-converting an input signal, a first filter having a predetermined frequency band and passing a frequency conversion signal from the first frequency converter; A second frequency converter for frequency converting a signal from one filter, and a second filter having a predetermined frequency band and passing the frequency signal from the second frequency converter. One of the first frequency converter and the second frequency converter is configured as a lower local, and the other is configured as an upper local, and at least one of the first filter and the second filter is integrated into an integrated circuit. A double conversion receiver characterized by using a filtered filter.   When the interference suppression on the high frequency side with respect to the input signal is determined by the sum of the suppression amount on the high frequency side of the first filter and the suppression amount on the low frequency side of the second filter, The interference wave suppression is determined by the sum of the suppression amount on the low frequency side of the first filter and the suppression amount on the high frequency side of the second filter, and the interference wave suppression on the high frequency side with respect to the input signal When determined by the sum of the amount of suppression on the low frequency side of one filter and the amount of suppression on the high frequency side of the second filter, the suppression of interference on the low frequency side is the amount of suppression on the high frequency side of the first filter. The double conversion receiver according to claim 1, wherein the double conversion receiver is determined by a sum of an amount of suppression and a suppression amount on a low frequency side of the second filter.   A semiconductor integrated circuit used in the double conversion receiver according to claim 1, wherein the first frequency converter, the second frequency converter, the first filter, and the second filter. A semiconductor integrated circuit comprising at least one integrated circuit.

Images