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US 6,472,925 B1Granted
Mixer circuit with negative feedback filtering
AssigneeMitsubishi Denki Kabushiki Kaisha
InventorsHiroshi Komurasaki, Hisayasu Satoh
Life of this patent
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Abstract
A mixer circuit having a high conversion gain which is excellent in linearity comprises an amplifier (1A) for amplifying one of two signals to be mixed with each other. The amplifier (1A) comprises a low-pass filter (14) not damping an input voltage (v1) of a frequency (f1) on a negative feedback circuit for its output. Due to the low-pass filter (14), it is possible to reduce harmonics by increasing the feedback amount as the frequency is increased.
Claims36
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal;
- and
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- an output terminal connected to the first input terminal of said mixer part;
- a first transistor connected to said amplifier input and output terminals and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said amplifier input and output terminals and having a second control electrode, a third current electrode and a fourth current electrode;
- and
- a low pass filter connected to the second and fourth current electrodes for reducing harmonics associated with a signal amplified by said first and second transistors.
6 more elements
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal;
- and
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- an output terminal connected to the first input terminal of said mixer part;
- a first transistor connected to said amplifier input and output terminals and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said amplifier input and output terminals and having a second control electrode, a third current electrode and a fourth current electrode;
- a first low pass filter connected in series between said second current electrode and a current source;
- and
- a second low pass filter connected in series between said fourth current electrode and a second current source.
7 more elements
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal;
- and
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- an output terminal connected to the first input terminal of said mixer part;
- a first transistor connected to said amplifier input and output terminals and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said amplifier input and output terminals and having a second control electrode, a third current electrode and a fourth current electrode;
- and
- a bandpass filter connected to the second current electrode and the fourth current electrode which aids in reducing harmonics and eliminating unnecessary low frequency components associated with the signal amplified by the first and second transistors.
6 more elements
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal;
- and
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- an output terminal connected to the first input terminal of said mixer part;
- a first transistor connected to said amplifier input and output terminals and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said amplifier input and output terminals and having a second control electrode, a third current electrode and a fourth current electrode;
- a first bandpass filter connected in series between said second current electrode and a current source;
- and
- a second bandpass filter connected in series between said fourth current electrode and a second current source;
- wherein said bandpass filters reduce harmonics and eliminate unnecessary low frequency components associated with the signal amplified by said first and second transistors.
8 more elements
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal, said mixer part further comprising:
- a first transistor connected to said first and second input terminals and said output terminal and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said first and second input terminals and said output terminal and having a second control electrode, a third current electrode and a fourth current electrode;
- a third transistor connected to said first and second input terminals and said output terminal and having a third control electrode, a fifth current electrode and a sixth current electrode;
- a fourth transistor connected to said first and second input terminals and said output terminal and having a fourth control electrode, a seventh current electrode and an eighth current electrode;
- and
- at least two low pass filters at least one of which is connected to the sixth and eighth current electrodes;
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- and
- an output terminal connected to the first input terminal of said mixer part;
- wherein said low pass filters reduce harmonics associated with the signal mixed by said transistors.
9 more elements
A mixer circuit comprising:
- a mixer part for mixing first and second signals received from first and second input terminals and comprising an output terminal for outputting a signal, said mixer part further comprising:
- a first transistor connected to said first and second input terminals and said output terminal and having a first control electrode, a first current electrode and a second current electrode;
- a second transistor connected to said first and second input terminals and said output terminal and having a second control electrode, a third current electrode and a fourth current electrode;
- a third transistor connected to said first and second input terminals and said output terminal and having a third control electrode, a fifth current electrode and a sixth current electrode;
- a fourth transistor connected to said first and second input terminals and said output terminal and having a fourth control electrode, a seventh current electrode and an eighth current electrode;
- and
- at least two bandpass filters, at least one of which is connected to the sixth and eighth current electrodes;
- an amplifier comprising:
- an input terminal for receiving a signal to be amplified;
- and
- an output terminal connected to the first input terminal of said mixer part;
- wherein said bandpass filters reduce both harmonics and unnecessary frequency components associated with the signal mixed by said transistors.
9 more elements
Dependencies are inferred from the claim text.