US 2019/0379356 A1 · POLYPHASE FILTER

Abstract

A first transistor (2a), a second transistor (2b), a third transistor (2c) and a fourth transistor (2d) are provided. A first transistor (2a) amplifies a first I signal VIP inputted from a first input terminal (1a). A second transistor (2b) amplifies a first Q signal VQP inputted from a second input terminal (1b). A third transistor (2c) amplifies a second I signal VIN when the second I signal VIN is inputted from a third input terminal (1c), the second I signal VIN forming a differential signal with the first I signal VIP. A fourth transistor (2d) amplifies a second Q signal VQN when the second Q signal VQN is inputted from a fourth input terminal (1d), the second Q signal VQN forming a differential signal with the first Q signal VQP.

Claims5

Dependent claims

1-10. (canceled)

A polyphase filter comprising:

a first transistor amplifying a first I signal inputted from a first input terminal;
a second transistor amplifying a first Q signal inputted from a second input terminal;
a third transistor amplifying a second I signal when the second I signal is inputted from a third input terminal, the second I signal forming a differential signal with the first I signal;
a fourth transistor amplifying a second Q signal when the second Q signal is inputted from a fourth input terminal, the second Q signal forming a differential signal with the first Q signal;
a first capacitor connected between an output terminal of the first transistor and the second input terminal;
a second capacitor connected between an output terminal of the second transistor and the third input terminal;
a third capacitor connected between an output terminal of the third transistor and the fourth input terminal;
and
a fourth capacitor connected between an output terminal of the fourth transistor and the first input terminal,
wherein an angular frequency determined in accordance with a transconductance of each of the first to fourth transistors and a capacitance of each of the first to fourth capacitors is changed by changing a current flowing through each of the first to fourth transistors, and
wherein each of the first to fourth transistors is a bipolar transistor whose base terminal is grounded,
an emitter terminal of the first transistor is connected to the first input terminal, and a collector terminal of the first transistor is the output terminal of the first transistor,
an emitter terminal of the second transistor is connected to the second input terminal, and a collector terminal of the second transistor is the output terminal of the second transistor,
an emitter terminal of the third transistor is connected to the third input terminal, and a collector terminal of the third transistor is the output terminal of the third transistor, and
an emitter terminal of the fourth transistor is connected to the fourth input terminal, and a collector terminal of the fourth transistor is the output terminal of the fourth transistor.

12 more elements

A polyphase filter comprising:

a first transistor amplifying a first I signal inputted from a first input terminal;
a second transistor amplifying a first Q signal inputted from a second input terminal;
a third transistor amplifying a second I signal when the second I signal is inputted from a third input terminal, the second I signal forming a differential signal with the first I signal;
a fourth transistor amplifying a second Q signal when the second Q signal is inputted from a fourth input terminal, the second Q signal forming a differential signal with the first Q signal;
a first capacitor connected between an output terminal of the first transistor and the second input terminal;
a second capacitor connected between an output terminal of the second transistor and the third input terminal;
a third capacitor connected between an output terminal of the third transistor and the fourth input terminal;
and
a fourth capacitor connected between an output terminal of the fourth transistor and the first input terminal,
wherein an angular frequency determined in accordance with a transconductance of each of the first to fourth transistors and a capacitance of each of the first to fourth capacitors by changing a current flowing through each of the first to fourth transistors, and
wherein each of the first to fourth transistors is a field-effect transistor whose gate terminal is grounded,
a source terminal of the first transistor is connected to the first input terminal, and a drain terminal of the first transistor is the output terminal of the first transistor,
a source terminal of the second transistor is connected to the second input terminal, and a drain terminal of the second transistor is the output terminal of the second transistor,
a source terminal of the third transistor is connected to the third input terminal, and a drain terminal of the third transistor is the output terminal of the third transistor, and
a source terminal of the fourth transistor is connected to the fourth input terminal, and a drain terminal of the fourth transistor is the output terminal of the fourth transistor.

12 more elements

Dependencies are inferred from the claim text.

Facts

Application

16/479,894Filed 2 Mar 2017

Published

12 Dec 2019

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

H03H 11/04
Multiple-port networks: frequency selective two-port networks
H03H 11/0422
Frequency selective two-port networks: using transconductance amplifiers, e.g. gmC filters
H03H 11/20
Networks for phase shifting: two-port phase shifters providing an adjustable phase shift
H03H 11/22
Networks for phase shifting: providing two or more phase shifted output signals, e.g. n-phase output

Polyphase filter

Life of this patent

Polyphase filter

Life of this patent

Abstract

Claims5