1. A wet-laid nonwoven fabric containing 15 mass % or more and 100 mass % or less of polyalkylene terephthalate or polyalkylene naphthalate staple fibers containing biomass-derived carbon ratio by radioactive carbon (carbon 14) measurement at 10% or more and 100% or less, single fiber fineness of 0.0001 to 7.0 decitex, and fiber length of 0.1 to 20 mm, wherein the staple fibers are low oriented staple fibers.
2. The wet-laid nonwoven fabric according to claim 1, wherein the wet-laid nonwoven fabric is composed of one type or two types or more of only staple fibers of polyalkylene terephthalate containing biomass-derived carbon ratio by radioactive carbon (carbon 14) measurement at 10% or more and 100% or less, single fiber fineness of 0.0001 to 7.0 decitex, and fiber length of 0.1 to 20 mm, or one type or two types or more of staple fibers of polyalkylene naphthalate containing biomass-derived carbon ratio by radioactive carbon (carbon 14) measurement at 10% or more and 100% or less, single fiber fineness of 0.0001 to 7.0 decitex, and fiber length of 0.1 to 20 mm, and wherein the wet-laid nonwoven fabrics contains low oriented staple fibers of 15 mass % or more and 100 mass % or less.
3. The wet-laid nonwoven fabric according to claim 1, wherein the staple fibers comprise fully oriented staple fibers (A) and low oriented staple fibers (B) contained at a weight ratio in a range of (A)(B)=1585 to 8515.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A differential amplifier circuit for improving linearity, comprising:
first and second loads;
a first output terminal for the first load;
a second output terminal for the second load;
a differential amplifying stage comprising a differential stage for amplifying a voltage difference between a first input stage and a second input stage, and a biasing current source for biasing the differential stage; and
a non-linearity filtering circuit for filtering a nonlinear signal generated from the differential amplifying stage, the non-linearity filtering circuit comprising a first cross circuit including a first transistor to connect the first and second output terminals, and a second cross circuit including a second transistor to connect the first and second output terminals,
wherein the first transistor has a drain connected to the second output terminal, a gate connected to the first output terminal, and a source connected to a ground;
the first cross circuit further includes a first bias voltage source stage for applying a first bias voltage to the gate of the first transistor;
the second transistor has a drain connected to the first output terminal, a gate connected to the second output terminal, and a source connected 5 to the ground; and
the second cross circuit further includes a second bias voltage source stage for applying a second bias voltage to the gate of the second transistor.
2. The differential amplifier circuit according to claim 1,
wherein:
the first bias voltage source stage includes a first capacitor connected between the gate of the first transistor and the first output terminal, and a first bias voltage source branched between the first capacitor and the gate of the first transistor; and
the second bias voltage source stage includes a second capacitor connected between the gate of the second transistor and the second output terminal, and a second bias voltage source branched between the second capacitor and the gate of the second transistor.
3. The differential amplifier circuit according to claim 1, wherein the differential stage includes a third transistor and a fourth transistor which constitute a differential pair.
4. The differential amplifier circuit according to claim 3, wherein: the differential stage further includes a first cascode transistor cascade-connected to the third transistor, and a second cascode transistor cascade-connected to the fourth transistor; and the first and second cascode transistors constitute a differential pair.
5. The differential amplifier circuit according to claim 4, wherein: the first cross circuit further includes a third cascode transistor connected to the first transistor; and the second cross circuit further includes a fourth cascode transistor connected to the second transistor.
6. The differential amplifier circuit according to claim 2, wherein the differential stage includes a third transistor and a fourth transistor which constitute a differential pair.
7. A frequency mixer for improving linearity, comprising:
first and second loads;
a first output terminal for the first load;
a second output terminal for the second load;
a differential amplifying stage comprising a differential stage for amplifying a voltage difference between a first input stage and a second input stage, and a biasing current source for biasing the differential stage;
a frequency mixing stage for modulating a frequency of an amplified signal output from the differential amplifying stage in accordance with a local oscillation signal, and outputting the resultant signal across the first and second output terminals; and
a non-linearity filtering circuit for filtering a non-linear signal generated from the differential amplifying stage, the non-linearity filtering circuit comprising a first cross circuit including a first transistor to connect a first mixing stage input terminal and a second mixing stage input terminal, and a second cross circuit including a second transistor to connect the first and second mixing stage input terminals.
8. The frequency mixer according to claim 7, wherein:
the first transistor has a drain connected to the second mixing stage input terminal, a gate connected to the first mixing stage input terminal, and a source connected to a ground;
the first cross circuit further includes a first bias voltage source stage for applying a first bias voltage to the gate of the first transistor;
the second transistor has a drain connected to the first mixing stage input terminal, a gate connected to the second mixing stage input terminal, and a source connected to the ground; and
the second cross circuit further includes a second bias voltage source stage for applying a second bias voltage to the gate of the second transistor.
9. The frequency mixer according to claim 8, wherein:
the first bias voltage source stage includes a first capacitor connected between the gate of the first transistor and the first mixing stage input terminal, and a first bias voltage source branched between the first capacitor and the gate of the first transistor; and
the second bias voltage source stage includes a second capacitor connected between the gate of the second transistor and the second mixing stage input terminal, and a second bias voltage source branched between the second capacitor and the gate of the second transistor.