Dual-band output switching high-frequency transmission circuit with a transmission mixer having two outputs
AssigneeNEC Compound Semiconductor Devices, Ltd.
InventorOsamu Shiraishi
Life of this patent
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Abstract
A transmission mixer (10) has a local input port (10LO) supplied with a local signal, an intermediate input port (10in) supplied with an input signal having an input frequency (fin) a first output port (10out1) for producing a first output signal having a first output frequency (fout1), and a second output port (10out2) for producing a second output signal having a second output frequency (fout2). The first and the second output ports (10out1, 10out2) are connected to first and second loads (LD1, LD2), respectively. The first load (LD1) is that where impedance-matching is made at the first output frequency (fout1) while the second load (LD2) is that where impedance-matching is made at the second output frequency (fout2).
Claims20
A transmission mixer for use in a dual band portable equipment to convert an intermediate frequency into a transmission frequency, said transmission mixer comprising:
- a local input port supplied with a local signal having a local frequency from a local oscillator;
- an intermediate input port supplied with an input signal having an input frequency which is equal to the intermediate frequency;
- a first output port for producing a first output signal having a first output frequency;
- and
- a second output port separate from the first output port for producing a second output signal having a second output frequency which is different from the first output frequency.
A dual-band output switching high-frequency transmission circuit for use in a dual-band portable equipment, said dual-band output switching high-frequency transmission circuit comprising:
- a first local oscillator for oscillating a first local signal having a first local frequency;
- a second local oscillator for oscillating a second local signal having a second local frequency which is different from the first local frequency;
- a transmission mixer comprising:
- a local input port selectively supplied with one of said first and said second local signals,
- an intermediate input port supplied with an input signal having an input frequency of an intermediate frequency, and
- first and second output ports separate from each other for producing first and second output signals having first and second output frequencies which are different from each other;
- a first band pass filter connected to said first output port and having a pass band of said first output frequency;
- and
- a second band pass filter connected to said second output port and having a pass band of said second output frequency.
Dependencies are inferred from the claim text.