WO2005099106A1 - Am受信回路 - Google Patents
Am受信回路 Download PDFInfo
- Publication number
- WO2005099106A1 WO2005099106A1 PCT/JP2005/002898 JP2005002898W WO2005099106A1 WO 2005099106 A1 WO2005099106 A1 WO 2005099106A1 JP 2005002898 W JP2005002898 W JP 2005002898W WO 2005099106 A1 WO2005099106 A1 WO 2005099106A1
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- Prior art keywords
- signal
- filter
- unit
- electric field
- broadcast wave
- Prior art date
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- 230000005236 sound signal Effects 0.000 claims abstract description 51
- 230000003321 amplification Effects 0.000 claims abstract description 31
- 238000003199 nucleic acid amplification method Methods 0.000 claims abstract description 31
- 238000001514 detection method Methods 0.000 claims abstract description 12
- 230000005684 electric field Effects 0.000 claims description 76
- 230000002238 attenuated effect Effects 0.000 claims description 11
- 230000007423 decrease Effects 0.000 claims description 3
- 238000012937 correction Methods 0.000 abstract description 36
- 230000001629 suppression Effects 0.000 abstract description 6
- 230000006870 function Effects 0.000 description 15
- 238000010586 diagram Methods 0.000 description 12
- 238000000034 method Methods 0.000 description 9
- 230000002452 interceptive effect Effects 0.000 description 4
- 230000010355 oscillation Effects 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 230000008447 perception Effects 0.000 description 2
- 230000000644 propagated effect Effects 0.000 description 2
- 239000000919 ceramic Substances 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 238000007689 inspection Methods 0.000 description 1
- 239000005433 ionosphere Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000035807 sensation Effects 0.000 description 1
Classifications
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- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G3/00—Gain control in amplifiers or frequency changers
- H03G3/20—Automatic control
- H03G3/30—Automatic control in amplifiers having semiconductor devices
- H03G3/3052—Automatic control in amplifiers having semiconductor devices in bandpass amplifiers (H.F. or I.F.) or in frequency-changers used in a (super)heterodyne receiver
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/16—Circuits
-
- H—ELECTRICITY
- H03—ELECTRONIC CIRCUITRY
- H03G—CONTROL OF AMPLIFICATION
- H03G5/00—Tone control or bandwidth control in amplifiers
- H03G5/16—Automatic control
- H03G5/165—Equalizers; Volume or gain control in limited frequency bands
-
- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B1/00—Details of transmission systems, not covered by a single one of groups H04B3/00 - H04B13/00; Details of transmission systems not characterised by the medium used for transmission
- H04B1/06—Receivers
- H04B1/10—Means associated with receiver for limiting or suppressing noise or interference
- H04B1/1027—Means associated with receiver for limiting or suppressing noise or interference assessing signal quality or detecting noise/interference for the received signal
- H04B1/1036—Means associated with receiver for limiting or suppressing noise or interference assessing signal quality or detecting noise/interference for the received signal with automatic suppression of narrow band noise or interference, e.g. by using tuneable notch filters
Definitions
- the present invention relates to an AM receiving circuit that performs sound quality correction of an audio signal according to the electric field strength of a broadcast wave signal.
- the AM (amplitude modulation) method is a method of transmitting a transmitted broadcast wave signal (modulated signal) by superimposing the broadcast wave signal (modulated signal) on the amplitude of a frequency (carrier) radiable from a broadcasting station. It is used for wave radio broadcasting (526.5-1606.5 kHz). Radio waves in the medium-wave broadcasting frequency band are not only propagated by surface waves, but also propagated by spatial waves reflected by the ionosphere (E layer) near 100 km above the ground, especially at night, so that a wide service area can be secured. The feature is that stable services can be provided for mobile objects such as cars.
- a super heterodyne detection method is generally used.
- Superheterodyne detection is a method in which a signal from a broadcasting station is combined with a signal from an oscillation (local oscillation) circuit built into the receiver, and the beat is detected, replaced with an intermediate frequency, amplified, and demodulated.
- Good in general, has the characteristic that high amplification gain can be easily obtained and interference can be easily prevented.
- a bandpass filter that allows only the frequency of the desired broadcast wave is required for the receiving circuit that receives the AM signal, but the center frequency is continuously changed without changing the band characteristics of the filter. Because it is very difficult to perform this, the superheterodyne detection method employs a method in which the local oscillation frequency is changed and only the intermediate frequency converted to a constant frequency is passed.
- the AM detection level fluctuates according to the electric field strength of the broadcast wave signal received from the antenna, and consequently interference may easily occur. is there.
- an AG for setting a gain in a front-end unit that processes a received RF (Radio Frequency) signal and an IF unit that processes an IF (Intermediate Frequency) signal A method has been proposed in which a C circuit is provided, and the above-mentioned gain is changed by the operation of an AGC circuit according to the electric field strength of the broadcast wave signal to suppress the occurrence of interference (for example, see Patent Document 1). This makes it possible to suppress the output fluctuation of the audio signal due to the fluctuation of the electric field strength of the broadcast wave signal.
- the AGC circuit operates to increase the gain when the electric field strength of the broadcast wave signal received from the antenna is weak.
- the proportion of noise generated from the amplifier and the like increases as the electric field strength of the broadcast wave signal received from the antenna decreases. That is, the SN ratio (Signal to Noise ratio) of the audio signal is reduced.
- Patent Document 1 JP-A-7-22975
- the AM receiver selects the desired station, and the desired station is selected.
- the frequency of the jamming station will affect the broadcast signal.
- the AGC circuit operates to lower both the reception levels of the signals from the desired station and the interfering station, and adjusts the gain in the front-end section and IF section so as to decrease. As a result, the desired station to be selected is suppressed by the influence of the interfering station.
- the gain of the AGC circuit may be increased.
- simply increasing the gain of the AGC circuit has a problem in that the saturation SN of the audio signal deteriorates due to the limitation of the dynamic range of the IF section.
- an object of the present invention is to provide an AM receiving circuit that improves suppression characteristics.
- a main invention for solving the above-mentioned problem is to provide a broadcast wave signal received by an antenna.
- An intermediate frequency amplifier that generates an intermediate frequency signal, amplifies and outputs the intermediate frequency signal, and an AGC (Automatic Gain Control) that sets a gain of the intermediate frequency amplifier according to the electric field strength of the broadcast wave signal.
- An AM detection section for detecting an intermediate frequency signal output from the intermediate frequency amplification section, a filter section for extracting a predetermined frequency band of the audio signal, and a filter section.
- An amplification unit that boosts or attenuates the audio signal of the predetermined frequency band extracted from the audio signal; and controls the filter characteristics of the filter unit and boosts or attenuates the amplification unit according to the electric field strength of the broadcast wave signal.
- a sound quality correction unit having a control unit for setting functions.
- FIG. 1 is a block diagram showing an AM receiving circuit of the present invention.
- FIG. 2 is a characteristic diagram showing a relationship between a received broadcast wave electric field intensity and an IF signal carrier wave intensity signal and a signal meter signal intensity.
- FIG. 3 is a block diagram showing a configuration of a sound quality correction unit applied to the AM receiving circuit of the present invention.
- FIG. 4 is a characteristic diagram showing characteristics of a low-pass filter (LPF) included in the audio correction unit.
- LPF low-pass filter
- FIG. 5 is a characteristic diagram illustrating characteristics of a high-pass filter (HPF) included in an audio correction unit.
- HPF high-pass filter
- FIG. 6 is a characteristic diagram showing boost and attenuate characteristics of an amplification unit included in the audio correction unit.
- FIG. 1 is a block diagram showing an AM receiving circuit of the present invention.
- FIG. 2 is a characteristic diagram showing a relationship between the strength of the IF signal carrier wave signal and the signal meter signal with respect to the received broadcast wave electric field strength.
- a broadcast wave signal is received by an antenna 12 and input to an FE (front end) unit 14.
- FE section front end
- the FE section 14 synchronously selects and outputs a broadcast wave (RF) signal.
- the FE section 14 may include an RF amplifier for amplifying the RF signal.
- the IF unit 16 has a function of converting a carrier wave frequency, outputs a local oscillator that outputs a signal different from a desired broadcast wave frequency by a predetermined frequency (usually 450 kHz), and outputs a signal different from the broadcast wave signal and the local oscillation signal. And a carrier that converts the carrier of the received broadcast wave signal into a predetermined intermediate frequency (usually 450 kHz). Further, the intermediate frequency is extracted by a band-pass filter (BPF) having the intermediate frequency as a center frequency, converted into an IF signal that is an amplitude modulation signal of the same information as the broadcast wave signal, amplified by an amplifier, and output. .
- BPF band-pass filter
- the IF unit 16 has a single-stage power generating IF signal having a carrier wave of 450 KHz, a first IF stage for up-conversion to 10.7 MHz, and a first IF signal obtained from the first IF stage.
- the IF signal of 10.7 MHz is the frequency used in the FM receiver circuit, and according to this configuration, the receiver that receives the AM broadcast wave signal and the FM broadcast wave signal can share the circuits after the IF section. it can.
- the input signal strength to the IF unit 16 is proportional to the strength of the broadcast wave signal received by the antenna 12, that is, the electric field strength of the broadcast wave signal, and depends on the receiving location and the receiving station. Changes, the output signal level also fluctuates, and the level of the output audio signal also fluctuates. Therefore, an IF-AGC circuit 18 (AGC section: automatic gain control circuit) for keeping the output signal level of the IF section 16 constant is provided.
- the IF-AGC circuit 18 receives a part of the output of the intermediate frequency signal output from the IF section 16 and inputs a direct current proportional to the amplitude with a diode.
- a current (AGC voltage: signal meter signal) is generated, and the gain of the amplifier of the IF unit 16 is controlled based on the signal meter signal. That is, the IF-AGC circuit 18 increases the gain of the amplifier of the IF section 16 when the electric field strength of the received broadcast wave signal is weak, and increases the amplifier of the IF section 16 when the electric field strength of the received broadcast wave signal is strong. , So that fluctuations in the electric field strength of the received broadcast wave signal do not appear as level fluctuations in the audio signal.
- the signal meter signal may be generated from the output of the first IF stage, or may be generated from the output of the second IF stage. Also, in a receiving circuit having a DSP (Digital Signal Processor) configuration for converting an IF signal into a digital signal and demodulating the signal, the signal may be generated by digital IF signal power calculation.
- DSP Digital Signal Processor
- the output signal of IF section 16 is input to AM detection section 20.
- the AM detector 20 removes the carrier component of the intermediate frequency signal output from the IF unit 16 and obtains the original modulated audio signal.
- the audio signal output from the AM detector 20 is input to the sound quality corrector 22.
- the sound quality correction unit 22 changes the frequency characteristics of the audio signal to correct the sound quality.
- Such sound quality correction is desirably performed according to the electric field strength of the received broadcast wave signal. For example, if the electric field strength of the received broadcast wave signal is sufficiently large, sound quality correction is not necessary. If the electric field strength of the received broadcast wave signal is low, the IF-AGC circuit 18 provides the IF section 16 with Since the gain of the amplifier circuit increases, the ratio of noise over a wide band generated by the power of the amplifier circuit increases relative to the audio signal.
- the band of the audio signal that deviates from the center frequency is attenuated to reduce the ratio of noise to the audio signal, to reduce the audible annoyance, or to increase the overall output level to reduce the audio signal. Make them easier to hear, or combine them.
- These corrections may be switched according to the electric field strength of the received broadcast wave signal, or the degree of correction may be changed in proportion to the electric field strength of the received broadcast wave signal.
- the sound quality correction unit 22 may be constituted by an analog circuit, or may be constituted by a DSP (Digital Signal Processor) that processes digital signals. The sound quality correction unit 22 will be described later in detail.
- the sound signal output from the sound quality correction unit 22 is sent to an amplifying circuit (not shown) at the subsequent stage. After being amplified, it is further output from a speaker or the like (not shown) at the subsequent stage.
- the electric field intensity of the received broadcast wave signal is detected based on the carrier intensity of the IF signal, and the sound quality correction unit 22 performs the detection when the electric field intensity of the received broadcast wave signal is weak.
- the sound quality is corrected according to the IF signal carrier strength.
- the IF signal carrier intensity is obtained by extracting the carrier frequency component of the IF signal output from the IF section 16 with a BPF 34 (intermediate frequency filter), and dividing the IF signal carrier by an integrator 36 into a DC voltage signal. (IF signal, carrier signal). Therefore, according to this method, since the intensity of the carrier frequency component of the IF signal is detected, even when the electric field intensity of the received broadcast wave signal is small, electric field intensity information reflecting the electric field intensity can be obtained. .
- the IF signal strength detection section 30 needs only to pass the IF carrier frequency component, it is desirable to use a BPF having a narrower band than the IF signal ceramic filter for the audio signal. Further, when the IF signal is converted to a digital signal, it is preferable to perform narrow band BPF processing by digital signal processing.
- FIG. 2 shows the intensity of the IF signal carrier wave intensity signal and the signal meter signal with respect to the electric field intensity of the received broadcast wave signal. If the electric field strength of the received broadcast wave signal is less than E1 (smaller than the specified value), the signal meter signal will not be output because the IF-AGC circuit 18 does not function due to the limit of the amplification factor of the amplifier. The IF signal carrier intensity signal is output.
- the IF signal carrier wave strength is information reflecting the electric field strength at this time.
- the electric field intensity (E1) at which the signal meter signal starts to be output is about 10 to 15 dB x V, although it differs depending on the circuit configuration of the FE section and the IF section of the receiving circuit.
- the present embodiment it is possible to obtain accurate electric field intensity information of a broadcast wave signal based on the IF signal carrier intensity even at a weak electric field intensity (E1 or less) at which a signal meter signal is not output.
- the sound quality can be optimally corrected according to the electric field strength.
- This configuration for detecting the electric field strength information of a broadcast wave signal is particularly useful in an AM receiving circuit as compared with an FM receiving circuit.
- the IF signal frequency The 50kHz carrier wave intensity is almost constant by the limiter amplifier circuit regardless of the electric field intensity.
- the AM receiving circuit if the electric field intensity of the received broadcast wave signal is weak, the IF signal wave This is because the reflection reflects the electric field strength of the wave signal.
- the sound quality correction unit 22 performs the sound quality correction based on the signal meter signal when the received broadcast wave electric field strength indicated by the horizontal axis in FIG. 2, that is, the electric field strength of the received broadcast wave signal is E1 or more. Is preferably performed.
- the electric field strength of the received broadcast wave signal is equal to or higher than E1
- the carrier strength of the IF signal output from the IF unit 16 by the IF-AGC circuit 18 becomes constant, and the strength of the carrier frequency component of the IF signal is received. It does not provide information on the electric field strength of the broadcast wave signal.
- the signal meter signal becomes information that reflects the electric field strength of the received broadcast wave signal
- the sound quality correction unit 22 performs sound quality correction based on the signal meter signal, thereby responding to the received broadcast wave electric field strength.
- appropriate sound quality correction can be performed.
- the sound quality correction unit 22 performs the sound quality correction based on the IF signal carrier strength when the received broadcast wave signal has a weak electric field strength, so that the received broadcast wave signal has a strong electric field strength.
- the operation based on the signal meter signal can be realized by adding both signals. This is because, as shown in FIG. 2, when the electric field strength of the received broadcast wave signal is weak (E1 or less), no signal meter signal is output, and when the electric field strength of the received broadcast wave signal is strong (E1 Above), the carrier strength of the IF signal is constant, and the sum of the two signals is the same regardless of whether the electric field strength of the received broadcast wave signal is weak (E1 or less) or strong (E1 or more).
- the IF signal carrier strength becomes a predetermined strength (for example, the strength corresponding to the electric field strength E1) or the signal meter signal strength becomes the predetermined strength (for example, the strength corresponding to the electric field strength E1) ) May be switched.
- the AM receiving circuit 10 includes an RF-AGC circuit (not shown), and controls the amplification factor of the RF amplifier provided in the FE unit 14 according to the output signal strength of the FE unit 14. Good.
- the RF-AGC circuit outputs an RF-AGC control voltage (RF-signal meter signal), which may be replaced with the signal meter signal output by the IF-AGC circuit 18 described above. Can be used as a signal meter signal by selecting, adding, combining, etc. it can.
- FIG. 3 is a block diagram showing a configuration of a sound quality correction unit applied to the AM receiving circuit of the present invention.
- FIG. 4 is a characteristic diagram showing characteristics of a low-pass filter (LPF) constituting the audio correction unit.
- FIG. 5 is a characteristic diagram illustrating characteristics of a high-pass filter (HPF) included in the audio correction unit. 4 and 5, the horizontal axis represents the electric field strength (dB x V) of the received broadcast wave signal, and the vertical axis represents the power and the degree of the filter. The strength of the filter in FIG.
- LPF low-pass filter
- HPF high-pass filter
- FIG. 6 is a characteristic diagram showing characteristics of an amplification unit included in the audio correction unit.
- the horizontal axis represents the reception intensity (dB / V) of the received broadcast wave signal
- the vertical axis represents the output level (dB) of the audio signal.
- FIG. 6 shows a characteristic line indicated by ⁇ , a characteristic line indicated by an order, a characteristic line indicated by X, and a characteristic line indicated by a mouth.
- the characteristic line indicated by ⁇ indicates that the amplification unit has boosted the input audio signal in a state where the control by the signal meter signal is “Yes”.
- the characteristic line indicated by the instruction indicates that the input audio signal was boosted with the signal meter signal controlled "None”.
- the characteristic line indicated by X indicates that the amplification unit attenuated the input silence signal (noise) with the signal meter signal control in the “Yes” state.
- the characteristic line indicated by a letter indicates that the input silence signal (noise) was attenuated with no signal meter signal control.
- the signal meter signal when using the signal meter signal for setting the boost function or the attenuate function in the amplifier, use the carrier signal of the IF signal when the electric field strength is E1 or less, and use the signal meter signal when the electric field strength is E1 or more. It shall be.
- the sound quality correction section 22 includes an LPF 42 (filter section, low-pass filter), an HPF 44 (filter section, high-pass filter), an amplification section 46, and a control section 48.
- the LPF 42 is provided for the purpose of reducing such noise perception in the sense of hearing. As shown in FIG. 4, the strength of the filter of the LPF 42 and the condition (filter characteristics) are controlled in accordance with the control output of the control unit 48 described later.
- the filter characteristics of the LPF42 show that as the electric field strength becomes weaker, the higher frequency band of the audio signal is attenuated more. It becomes.
- HPF44 is provided to prevent such an imbalance in auditory sound.
- the strength of the filter (filter characteristics) of the HPF 44 is controlled in accordance with the control output of the control unit 48 described later. For example, when the electric field strength of the received broadcast wave signal is in the range of about 10-35 dB / iV, the filter characteristics of the HPF44 show that the lower the electric field strength, the more the lower frequency band of the audio signal is attenuated. Characteristics.
- the audio signal that has passed through the LPF 42 and the HPF 44 has an effect on the high-frequency band and the low-frequency band that deviate from the center frequency of the audio signal in accordance with the electric field strength of the received broadcast wave signal. It becomes a signal that is attenuated.
- LPF42 and HPF44 since the filter characteristics of LPF42 and HPF44 change when the electric field strength of the received broadcast signal is in the range of E1 or more, LPF42 and HPF44 output the signal output from IF-AGC circuit 18. The filter characteristics are controlled according to the intensity of the meter signal.
- the amplification section 46 is set to either a boost function for boosting the audio signal passing through the HPF 44 or an attenuation function for attenuating the audio signal.
- the setting of the boost function or the attenuate function in the amplification section 46 is performed by the control section 48 described above.
- the gain of the amplifier circuit of the IF unit 16 is controlled by the IF-AGC circuit 18 and becomes smaller.
- AM inspection From the wave unit 20 an audio signal in a state of being suppressed is output. Therefore, the amplifier 46 receives either the signal from the IF-AGC circuit 18 or the signal from the integrator 36 at the time when the channel is selected and suppressed.
- a boost function having a predetermined amplification factor is set.
- the audio signal that has passed through the LPF 42 and the HPF 44 and effectively attenuated the high-frequency and low-frequency components is boosted as shown in FIG.
- the audio signal output from the AM detector 20 If no sound quality correction is performed, the level of the audio signal will be reduced, which may worsen the noise sensation.
- the amplification section 46 in the audio correction section 22 does not simply increase the gain of the amplification circuit of the IF section 16. Since boosting is performed, the suppression characteristics are improved, and it is possible to reduce the noise, muffledness, and deterioration of the audibility of the audio signal.
- the gain of the amplifier circuit of the IF unit 16 is changed to the IF—AGC circuit 18. Controlled to grow.
- the AM detection unit 20 outputs a sound signal that is only noise in terms of hearing. Therefore, the amplifier 46 receives the signal meter signal output from the IF-AGC circuit 18 or the carrier signal intensity signal output from the integrator 36, thereby providing an attenuation function having a predetermined attenuation rate. Is set. As a result, the audio signal that has passed through the LPF 42 and the HPF 44 and effectively attenuated the high-frequency and low-frequency components is attenuated as shown in FIG.
- the sense of noise may deteriorate. It becomes.
- an electric field strength at which the SN ratio cannot be obtained for example, 20 dB x V
- the sense of noise may deteriorate. It becomes.
- attenuation is performed in the amplification unit 46 in the audio correction unit 22 regardless of the gain of the amplification circuit of the IF unit 16. In addition, it is possible to reduce discomfort due to noise.
- the control unit 48 includes, for example, a signal meter signal output from the IF-AGC circuit 18 and an integrator.
- the control signal output from the control unit 48 according to the electric field strength of the broadcast wave signal is input commonly to the LPF 42, HPF 44, and the amplification unit 46, and the filter characteristics of the LPF 42, HPF 44 and the boost of the amplification unit 46 are boosted.
- the setting of the function or the attenuation function can be executed simultaneously.
- control unit 48 may receive only the signal meter signal.
- An AM receiver including an IF-AGC circuit 18 for setting the gain of the amplifier circuit in the IF section 16 according to the electric field strength, and an AM detection section 20 for detecting an intermediate frequency signal output from the IF section 16.
- the sound quality correction unit 22 includes a control unit 48 that controls the filter characteristics of the filter units 42 and 44 and sets the boost function or the attenuate function of the amplification unit 48 according to the strength.
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- Noise Elimination (AREA)
Abstract
Description
Claims
Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/599,456 US7664197B2 (en) | 2004-03-30 | 2005-02-23 | AM receiving circuit |
KR1020067020525A KR101110686B1 (ko) | 2004-03-30 | 2005-02-23 | Am수신회로 |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
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JP2004099360A JP4282524B2 (ja) | 2004-03-30 | 2004-03-30 | Am受信回路 |
JP2004-099360 | 2004-03-30 |
Publications (1)
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WO2005099106A1 true WO2005099106A1 (ja) | 2005-10-20 |
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Application Number | Title | Priority Date | Filing Date |
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PCT/JP2005/002898 WO2005099106A1 (ja) | 2004-03-30 | 2005-02-23 | Am受信回路 |
Country Status (5)
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US (1) | US7664197B2 (ja) |
JP (1) | JP4282524B2 (ja) |
KR (1) | KR101110686B1 (ja) |
CN (1) | CN1938958A (ja) |
WO (1) | WO2005099106A1 (ja) |
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KR20080088302A (ko) * | 2007-03-29 | 2008-10-02 | 삼성전자주식회사 | 이상 변조 신호 처리 방법 및 이상 변조 신호 보상 기능을가지는 수신기 |
US9130683B2 (en) | 2011-03-07 | 2015-09-08 | Texas Instruments Incorporated | Silence based attenuation for enhanced idle-channel FM or other receiver co-existence with a coexisting radio and circuits, processes, and systems |
US8805312B2 (en) | 2011-04-06 | 2014-08-12 | Texas Instruments Incorporated | Methods, circuits, systems and apparatus providing audio sensitivity enhancement in a wireless receiver, power management and other performances |
JP5085769B1 (ja) | 2011-06-24 | 2012-11-28 | 株式会社東芝 | 音響制御装置、音響補正装置、及び音響補正方法 |
JPWO2014115388A1 (ja) * | 2013-01-22 | 2017-01-26 | クラリオン株式会社 | 受信装置および受信装置の制御方法 |
JP6279441B2 (ja) * | 2014-09-24 | 2018-02-14 | アルパイン株式会社 | ラジオ受信機 |
JP7000945B2 (ja) * | 2018-03-23 | 2022-01-19 | 株式会社Jvcケンウッド | 無線通信機 |
JP7108557B2 (ja) | 2019-02-08 | 2022-07-28 | 株式会社Subaru | リレー装置 |
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2004
- 2004-03-30 JP JP2004099360A patent/JP4282524B2/ja not_active Expired - Fee Related
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2005
- 2005-02-23 KR KR1020067020525A patent/KR101110686B1/ko not_active IP Right Cessation
- 2005-02-23 CN CNA2005800102593A patent/CN1938958A/zh active Pending
- 2005-02-23 WO PCT/JP2005/002898 patent/WO2005099106A1/ja active Application Filing
- 2005-02-23 US US10/599,456 patent/US7664197B2/en not_active Expired - Fee Related
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JPH04207231A (ja) * | 1990-11-28 | 1992-07-29 | Matsushita Electric Ind Co Ltd | Amラジオ受信装置 |
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JP2005079870A (ja) * | 2003-08-29 | 2005-03-24 | Sanyo Electric Co Ltd | Am受信回路 |
Also Published As
Publication number | Publication date |
---|---|
US7664197B2 (en) | 2010-02-16 |
JP2005286789A (ja) | 2005-10-13 |
US20070206706A1 (en) | 2007-09-06 |
CN1938958A (zh) | 2007-03-28 |
KR20070004807A (ko) | 2007-01-09 |
KR101110686B1 (ko) | 2012-02-24 |
JP4282524B2 (ja) | 2009-06-24 |
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