Frequency conversion circuit
First Claim
1. A circuit array for frequency translation of an input signal using the principle of quadrature signal processing, comprising:
- first mixer means for mixing a first portion of the input signal with a first quadrature heterodyne signal;
second mixer means for mixing a second portion of the input signal with a second quadrature heterodyne signal which is shifted 90°
in phase with respect to the first quadrature heterodyne signal; and
heterodyne signal generator means for generating the first and second quadrature heterodyne signals, the heterodyne signal generator means including a first portion which is connected to the first and second mixer means and a second portion which is connected to the first portion and which receives a local oscillator signal, the first portion of the heterodyne signal generator means having a first control loop means for stabilizing the 90°
phase shift between the first and second quadrature heterodyne signals,wherein the second portion of the heterodyne signal generator means includes amplifier means for generating an amplified local oscillator signal, the amplified local oscillator signal having a keying ratio, and means for adjusting the keying ratio to 0.5, the means for adjusting having a second control loop which includes a symmetry detector, the amplified local oscillator signal being conveyed to the first portion of the heterodyne signal generator means.
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Accused Products
Abstract
A circuit array for frequency translation by means of quadrature heterodyne signals has very low quadrature errors even at very high frequencies and is monolithically integratable with little external circuitry. The circuit array includes a first mixer which receives a first portion of an input signal, a second mixer which receives a second portion of the input signal, and a heterodyne signal generator which receives a local oscillator signal and supplies quadrature heterodyne signals to the mixers. The heterodyne signal generator includes a control loop to ensure a 90° phase shift between the quadrature heterodyne signals. The circuit array can be used in a modulator for a transmitter or in a demodulator for a receiver.
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Citations
11 Claims
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1. A circuit array for frequency translation of an input signal using the principle of quadrature signal processing, comprising:
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first mixer means for mixing a first portion of the input signal with a first quadrature heterodyne signal; second mixer means for mixing a second portion of the input signal with a second quadrature heterodyne signal which is shifted 90°
in phase with respect to the first quadrature heterodyne signal; andheterodyne signal generator means for generating the first and second quadrature heterodyne signals, the heterodyne signal generator means including a first portion which is connected to the first and second mixer means and a second portion which is connected to the first portion and which receives a local oscillator signal, the first portion of the heterodyne signal generator means having a first control loop means for stabilizing the 90°
phase shift between the first and second quadrature heterodyne signals,wherein the second portion of the heterodyne signal generator means includes amplifier means for generating an amplified local oscillator signal, the amplified local oscillator signal having a keying ratio, and means for adjusting the keying ratio to 0.5, the means for adjusting having a second control loop which includes a symmetry detector, the amplified local oscillator signal being conveyed to the first portion of the heterodyne signal generator means. - View Dependent Claims (2, 3, 11)
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4. A circuit array for frequency translation of an input signal using the principle of quadrature signal processing, comprising:
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first mixer means for mixing a first portion of the input signal with a first quadrature heterodyne signal; second mixer means for mixing a second portion of the input signal with a second quadrature heterodyne signal which is shifted 90°
in phase with respect to the first quadrature heterodyne signal; andheterodyne signal generator means for generating the first and second quadrature heterodyne signals, the heterodyne signal generator means including a first portion which is connected to the first and second mixer means and a second portion which is connected to the first portion and which receives a local oscillator signal, the first portion of the heterodyne signal generator means having a first control loop means for stabilizing the 90°
phase shift between the first and second quadrature heterodyne signals,wherein the first portion of the heterodyne signal generator means includes a frequency doubler to double the frequency of the local oscillator signal, and a master-slave D flip-flop in series with the frequency doubler, the flip-flop having a master stage with an output that supplies one of the quadrature heterodyne signals and having a slave stage with an output port that supplies the other of the quadrature heterodyne signals, and wherein the first control loop means includes a phase detector to detect the relative phases of the quadrature heterodyne signals. - View Dependent Claims (5, 6, 7, 8)
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9. A circuit array for frequency translation of a high frequency input signal using the principle of quadrature signal processing, in combination with means connected to a receiving antenna for generating the input signal,
wherein the circuit array for frequency translation of the input signal includes first mixer means for mixing a first portion of the input signal with a first quadrature heterodyne signal, second mixer means for mixing a second portion of the input signal with a second quadrature heterodyne signal which is shifted 90° - in phase with respect to the first quadrature heterodyne signal, and
heterodyne signal generator means for generating the first and second quadrature heterodyne signals, the heterodyne signal generator means including a first portion which is connected to the first and second mixer means and a second portion which is connected to the first portion and which receives a local oscillator signal, the first portion of the heterodyne signal generator means having a first control loop means for stabilizing the 90°
phase shift between the first and second quadrature heterodyne signals, andwherein the means connected to the receiving antenna includes a preamplifier, means responsive to the preamplifier for generating the first and second portions of the input signal, the means responsive to the preamplifier including a voltage/current converter having a controllable amplification factor, the voltage/current converter receiving the input signal from the preamplifier and providing an output current, and divider means for supplying the output current of the voltage/current converter in equal parts to the first and second mixer means. - View Dependent Claims (10)
- in phase with respect to the first quadrature heterodyne signal, and
Specification