Active image separation mixer
First Claim
1. An image separating mixer apparatus comprising:
- a first phase shift circuit for receiving a first input signal of at least a first and second frequency, said first phase shift circuit providing separate first and second output signals;
a signal division and amplification circuit for receiving a second input signal of at least a third frequency, said signal division and amplification circuit comprising first and second active amplification elements each receiving at inputs thereof a portion of said second input signal and having, respectively, first and second separated outputs providing, respectively, separated third and fourth output signals;
a mixing circuit coupled between said first phase shift circuit and said signal division and amplification circuit, said mixing circuit having separated inputs for receiving, respectively, said first and second output signals from the first phase shift circuit for mixing with said separated third and fourth output signals from said signal division and amplification circuit to provide fifth and sixth separated output signals of a fourth frequency derived from said first and second input signals, said mixing circuit having first and second active mixing elements, wherein said active amplification elements and said active mixing elements are different devices with individual inputs; and
a second phase shift circuit coupled to said mixing circuit for receiving said separated fifth and sixth output signals at separated inputs of said second phase shift circuit, said second phase shift circuit providing separated seventh and eight output signals of said fourth frequency corresponding, respectively, to said first and second frequencies.
1 Assignment
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Accused Products
Abstract
A mixer separates IF components IF1, IF2 of the same frequency which are images of different frequency RF signals RF1, RF2 beating with a given LO signal. The LO signal is applied to a FET active power divider and applied to the drains of a pair of balanced FET mixing elements. The FETs for the active power divider are built from the same device structure as the FETs for the mixing elements sharing drain nodes. The RF signals are passed through a quadrature phase shifter and applied to the gates of the FET mixing elements. The mixed signals appear at the drains of FET mixing elements are applied to opposing ports of a second quadrature hybrid at whose output ports the separated IF output signals IF1, IF2 appear.
159 Citations
25 Claims
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1. An image separating mixer apparatus comprising:
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a first phase shift circuit for receiving a first input signal of at least a first and second frequency, said first phase shift circuit providing separate first and second output signals; a signal division and amplification circuit for receiving a second input signal of at least a third frequency, said signal division and amplification circuit comprising first and second active amplification elements each receiving at inputs thereof a portion of said second input signal and having, respectively, first and second separated outputs providing, respectively, separated third and fourth output signals; a mixing circuit coupled between said first phase shift circuit and said signal division and amplification circuit, said mixing circuit having separated inputs for receiving, respectively, said first and second output signals from the first phase shift circuit for mixing with said separated third and fourth output signals from said signal division and amplification circuit to provide fifth and sixth separated output signals of a fourth frequency derived from said first and second input signals, said mixing circuit having first and second active mixing elements, wherein said active amplification elements and said active mixing elements are different devices with individual inputs; and a second phase shift circuit coupled to said mixing circuit for receiving said separated fifth and sixth output signals at separated inputs of said second phase shift circuit, said second phase shift circuit providing separated seventh and eight output signals of said fourth frequency corresponding, respectively, to said first and second frequencies. - View Dependent Claims (2, 3, 4, 5)
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6. An image separating mixer apparatus comprising:
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a first phase shift circuit for receiving a first input signal of at least a first and second frequency, said first phase shift circuit providing first and second output signals; a signal division and amplification circuit for receiving a second input signal of at least a third frequency, said signal division and amplification circuit providing third and fourth output signals, said signal division and amplification circuit having first and second active amplification elements; a mixing circuit coupled between said first phase shift circuit and said signal division and amplification circuit, said mixing circuit for mixing said first and second output signals from the first phase shift circuit with said third and fourth output signals from said signal division and amplification circuit to provide separated fifth and sixth output signals of a fourth frequency derived from said first and second input signals, said mixing circuit having first and second active mixing elements, wherein said first and second active mixing elements are transistor devices; a second phase shift circuit coupled to said mixing circuit for receiving said fifth and sixth output signals, said second phase shift circuit providing separated seventh and eighth output signals of said fourth frequency corresponding, respectively, to said first and second frequencies; and wherein said first active mixing element and said first active amplification element have different transconductances and comprise a first integrated device sharing a first output region and having separate input regions corresponding to said first active mixing element and said first active amplification element, respectively; and wherein said second active mixing element and said second active amplification element have different transconductances and comprise a second integrated device sharing a second output region and having separate input regions corresponding to said second active mixing element and said second active amplification element, respectively. - View Dependent Claims (7)
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8. An image separating mixer apparatus comprising:
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a first phase shift circuit for receiving a first input signal of at least a first and second frequency, said first phase shift circuit providing first and second output signals; a signal division and amplification circuit for receiving a second input signal of at least a third frequency, said signal division and amplification circuit providing third and fourth output signals, said signal division and amplification circuit having first and second active amplification elements; a mixing circuit coupled between said first phase shift circuit and said signal division and amplification circuit, said mixing circuit for mixing said first and second output signals from the first phase shift circuit with said third and fourth output signals from said signal division and amplification circuit to provide separated fifth and sixth output signals of a fourth frequency derived from said first and second input signals, said mixing circuit having first and second active mixing elements, wherein said first and second active mixing elements and said first and second active amplification elements are field effect transistors, said field effect transistors each having a gate region, a source region and a drain region; a second phase shift circuit coupled to said mixing circuit for receiving said fifth and sixth output signals, said second phase shift circuit providing separated seventh and eighth output signals of said fourth frequency corresponding, respectively, to said first and second frequencies; and wherein said first active mixing element and said first active amplification element have different transconductances and comprise a first integrated device sharing a first drain region, said first integrated device having separate gates regions corresponding to said first active mixing element and said first active amplification element, respectively; and wherein said second active mixing element and said second active amplification element have different transconductances and comprise a second integrated device sharing a second drain region, said second integrated device having separate gate regions corresponding to said second active mixing element and said second active amplification element, respectively. - View Dependent Claims (9, 10, 11)
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12. An image separating mixer apparatus comprising:
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a first phase shift circuit for receiving a first input signal of at least a first and second frequency, said first phase shift circuit providing first and second output signals; a signal division and amplification circuit for receiving a second input signal of at least a third frequency, said Signal division and amplification circuit providing third and fourth output signals, said signal division and amplification circuit having first and second active amplification elements; a mixing circuit coupled between said first phase shift circuit and said signal division and amplification circuit, said mixing circuit for mixing said first and second output signals from the first phase shift circuit with said third and fourth output signals from said signal division and amplification circuit to provide separated fifth and sixth output signals of a fourth frequency derived from said first and second input signals, said mixing circuit having first and second active mixing elements, and; a second phase shift circuit coupled to said mixing circuit for receiving said fifth and sixth output signals, said second phase shift circuit providing separated seventh and eighth output signals of said fourth frequency corresponding, respectively, to said first and second frequencies; and further comprising a filter circuit coupling said mixing circuit to said second phase shift circuit, said filter circuit having a pass-band including said fourth frequency and a stop band including at least one of said first, second or third frequencies. - View Dependent Claims (13)
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14. A method for mixing an RF input signal of a first and second frequency with a LO input signal of at least a third frequency to produce an output IF signal of a fourth frequency having first and second separated components corresponding to said first and second RF frequencies, respectively, comprising:
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coupling said RF input signal to a first phase shift circuit which provides first and second RF output signals; coupling said LO input signal to a signal division and amplification circuit having first and second active amplification elements having outputs which provide first and second LO output signals; supplying said first RF output signal and said first LO output signal to a first-active mixing element; supplying said second RF output signal and said second LO output signal to a second active mixing element separate from said first active mixing element; separately coupling first and second intermediate IF signals appearing at separated outputs of said separate first and second active mixing elements to different inputs of a second phase shift circuit; and obtaining from said second phase shift circuit, said first and second separated components of said output IF signals corresponding to said first and second RF frequencies, respectively. - View Dependent Claims (15, 16, 17, 18, 19, 20, 21, 22, 23, 24)
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25. A method of separating image signals created from mixing an LO input signal of a first frequency with an RF input signal of at least a second and third frequency comprising:
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dividing said RF input signal into first and second substantially identical RF output signals having a relative phase difference of substantially ninety degrees; dividing and amplifying said LO input signal into two substantially identical LO output signals having a relative phase difference of substantially zero degrees, said two substantially identical LO output signals appearing, respectively, at first and second separated output regions of first and second transistors; providing said RF output signals to input regions of active mixing elements, said active mixing elements comprising third and fourth transistors having third and fourth separated output regions in common, respectively, with said first and second output regions, wherein said first and third output regions form a first common region, and said second and said fourth output regions form a second common region; and combining separate intermediate IF signals appearing, respectively, at said first and second common regions to produce separated IF output signals of said fourth frequency corresponding to said second and third frequencies of said RF input signal.
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Specification