High frequency signal receiver

• US 7,373,132 B2
• Filed: 06/16/2004
• Issued: 05/13/2008
• Est. Priority Date: 06/18/2003
• Status: Expired due to Fees

• Current Assignee: Sony Corporation (Sony Group Corp.)
• Original Assignee: Sony Corporation (Sony Group Corp.)
• Inventors: Shimanuki, Masaru
• Primary Examiner(s): NGUYEN, THUAN T
• Application Number:
  US10/869,140
• Publication Number:
  US 20050028210A1
• Time in Patent Office: 1,427 Days
• Field of Search: 455/324, 455/102, 455/103, 455/115, 455/118, 455/126, 455/127, 455/129, 455/295, 375/285, 375/346, 375/350, 327/103, 327/124, 327/143
• US Class Current: 455/324
• CPC Class Codes: H03D 7/165 at least two frequency changers being located in different paths, e.g. in two paths with carriers in quadrature combined with amplitude demodulation H03D1/2245, combined with angle demodulation H03D3/007; N-path filters H03H19/002
• CPC Class Codes: H03J 3/185 with varactors, i.e. voltage variable reactive diodes
• CPC Class Codes: H03J 3/24 of more than one resonant circuit simultaneously, the circuits being tuned to substantially the same frequency, e.g. for single-knob tuning
• CPC Class Codes: H03L 7/0805 the loop being adapted to provide an additional control signal for use outside the loop
• CPC Class Codes: H03L 7/18 using a frequency divider or counter in the loop H03L7/20, H03L7/22 take precedence
• CPC Class Codes: H04B 1/18 Input circuits, e.g. for coupling to an antenna or a transmission line coupling networks between antennas or lines and receivers independent of the nature of the receiver H03H

Abstract

A high frequency signal receiver can prevent higher harmonics other than a necessary higher harmonic from being subjected to frequency conversion so as to interfere with the base band signal in a broadcasting channel frequency band. The receiver has a high frequency signal receiving circuit 1 that comprises an input circuit 3 to which a high frequency signal (RF signal) subjected to frequency conversion from a 12 GHz band to a 1 to 2 GHz band is input, a mixer circuit 4 adapted to frequency convert the signal of 1 to 2 GHz band output from the input circuit 3 into a base band signal, a local oscillation output circuit section 5 adapted to supply a signal of a frequency band to be mixed with the signal output of the input circuit 3 to the mixer circuit 4 and a PLL circuit section 6 to which the source oscillation output signal from the local oscillation output circuit section 5 is input. The local oscillation output circuit section 5 has an oscillation circuit 51, a higher harmonic output circuit 52 that generates the fourth harmonic of the output signal of the oscillation circuit 51 and a resonance circuit 53. It controls both the resonance frequency of the resonance circuit 53 of the local oscillation output circuit section 5 and the frequency characteristic of the input circuit 3 by means of the control voltage output from the PLL circuit section 6 so as to boost the higher harmonic of an order that corresponds to desired broadcasting channel frequency and attenuate higher harmonics of all other orders that appear in other frequency bands that overlap the broadcasting channel frequency in the input circuit 3.

Claims

1. A direct conversion type high frequency signal receiver adapted to convert the high frequency signal obtained by receiving a digital broadcast signal from a broadcasting satellite or a communications satellite into a base band signal by frequency conversion, the receiver comprising:

an input circuit for inputting high frequency signals;

a mixer circuit for converting a signal having a desired frequency and obtained from the input circuit into a base band signal by frequency conversion; and

a local oscillation output circuit section for supplying the mixer circuit with a signal having a desired frequency to be mixed with the signal from the input circuit;

the local oscillation output circuit section having an source oscillator and a higher harmonic output circuit for taking out a higher harmonic of the output signal of the source oscillator as a signal having a desired frequency;

the input circuit having a frequency characteristic of removing all the higher harmonics of the output signal other than the higher harmonic having the desired frequency.

2. A receiver according to claim 1, further comprising;

a PLL circuit section for receiving an source oscillation output signal of the source oscillator of the local oscillation output circuit section;

the control voltage from the PLL circuit section being used to control the resonance frequency of the source oscillator of the local oscillation output circuit section and the frequency characteristic of the input circuit.

3. A receiver according to claim 2, wherein the PLL circuit section has a frequency divider for dividing the frequency of the source oscillation output signal from the source oscillator of the local oscillation output circuit section by a dividing ratio corresponding to a station selection signal, a phase comparator for comparing the output from the frequency divider with a reference frequency and a frequency-voltage converter for converting the output signal from the phase comparator into the control voltage.

4. A receiver according to claim 2, wherein

a resonance circuit is connected to the source oscillator of the local oscillation output circuit section and the resonance frequency of the resonance circuit is controlled by the control voltage from the PLL circuit section, and

the input circuit has a characteristic of boosting the higher harmonic of the broadcasting channel frequency to be used for the desired frequency and attenuating higher harmonics other than the higher harmonic found around other broadcasting channel frequencies, the frequency to be boosted and the frequencies to be attenuated being controlled by the control voltage from the PLL circuit section.

5. A receiver according to claim 1, wherein

the higher harmonic output circuit of the local oscillation output circuit section is adapted to take out the fourth harmonic of the source oscillation output signal from the source oscillator, and

the input circuit is adapted to remove the third harmonic of the source oscillation output signal.