SEMICONDUCTOR DEVICE

• US 20170149393A1
• Filed: 02/08/2017
• Published: 05/25/2017
• Est. Priority Date: 09/09/2014
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: MIZOKAMI, Masakazu
• Granted Patent: US 9,991,855 B2
• Time in Patent Office: Days
• CPC Class Codes: H03F 1/565 using inductive elements
• CPC Class Codes: H03F 2200/111 the amplifier being a dual or triple band amplifier, e.g. 900 and 1800 MHz, e.g. switched or not switched, simultaneously or not
• CPC Class Codes: H03F 2200/294 the amplifier being a low noise amplifier [LNA]
• CPC Class Codes: H03F 2200/336 A I/Q, i.e. phase quadrature, modulator or demodulator being used in an amplifying circuit
• CPC Class Codes: H03F 2200/429 Two or more amplifiers or one amplifier with filters for different frequency bands are coupled in parallel at the input or output
• CPC Class Codes: H03F 2200/451 the amplifier being a radio frequency amplifier
• CPC Class Codes: H03F 2200/537 A transformer being used as coupling element between two amplifying stages
• CPC Class Codes: H03F 2203/21109 An input signal being distributed by switching to a plurality of paralleled power amplifiers
• CPC Class Codes: H03F 2203/21112 A filter circuit being added at the input of a power amplifier stage
• CPC Class Codes: H03F 2203/7209 the gated amplifier being switched from a first band to a second band
• CPC Class Codes: H03F 3/19 with semiconductor devices only
• CPC Class Codes: H03F 3/211 using a combination of several amplifiers H03F3/60 takes precedence
• CPC Class Codes: H03F 3/45188 Non-folded cascode stages
• CPC Class Codes: H03F 3/72 Gated amplifiers, i.e. amplifiers which are rendered operative or inoperative by means of a control signal
• CPC Class Codes: H04B 1/16 Circuits

Abstract

In a semiconductor device, received signals of different frequency bands are input selectively to low noise amplifiers. A plurality of primary inductors are coupled between differential output nodes of the respective low noise amplifiers. A secondary inductor is provided commonly for the primary inductors, and magnetically coupled to the primary inductors. A demodulator converts a received signal transmitted from one of the primary inductors to the secondary inductor by electromagnetic induction, into a signal of a low frequency.

Claims

1. A wireless communication system comprising:

a antenna;

a plurality of switches connected to the antenna;

a plurality of primary inductors each of which receives received signals from the plurality of switches;

a secondary inductor which is provided commonly for the primary inductors, and magnetically coupled to each of primary inductors; and

a demodulator which converts a signal transmitted from one of the primary inductors to the secondary inductor by electromagnetic induction, into a signal of a low frequency.

2. The wireless communication system according to claim 1, further comprising

a plurality of low noise amplifiers, and

wherein at least one of the low noise amplifiers corresponds to each of the primary inductors, and

wherein each of the primary inductors is coupled between differential output nodes of a corresponding one or the plurality of low noise amplifiers.

3. The wireless communication system according to claim 2,

wherein each of the low noise amplifiers switches between an activation state in which an input signal can be amplified and an inactivation state in which an input signal is interrupted,

wherein the semiconductor device further includes a control unit,

wherein the control unit is configured to select one of the low noise amplifiers, control the selected low noise amplifier to be in the activation state, and control rest of low noise amplifiers to be in the inactivation state, thereby transmitting the signal input to the selected low noise amplifier to the secondary inductor.

4. The wireless communication system according to claim 3, further comprising

a plurality of first variable capacitance elements which respectively correspond to the primary inductors, and are coupled in series respectively to the corresponding primary inductors.

5. The wireless communication system according to claim 4,

wherein the control unit is configured to set a capacitance value of each of the corresponding first variable capacitance elements, in a manner that a parallel resonance circuit is configured with the primary inductor corresponding to the selected low noise amplifier and the first variable capacitance element at a frequency of the signal input to the selected low noise amplifier.

6. The wireless communication system according to claim 5,

wherein the control unit is configured to set a capacitance value of rest of the first variable capacitance element except the first variable capacitance element corresponding to the selected low noise amplifier, to a possible minimum value.

7. The wireless communication system according to claim 4, further comprising:

a plurality of second variable capacitance elements respectively corresponding to all pairs of the primary inductors; and

a plurality of third variable capacitance elements respectively corresponding to all pairs of the primary inductors,

wherein each of the second variable capacitance elements is coupled between first ends of a corresponding pair of primary inductors, and

wherein each of the second variable capacitance elements is coupled between second ends of a corresponding pair of primary inductors.

8. The wireless communication system according to claim 7,

wherein the control unit is configured to set a capacitance element of each of the second and third variable capacitance elements, in a manner that a series resonance circuit is configured with the second and third variable capacitance elements coupled between the primary inductor corresponding to the selected low noise amplifier and a non-corresponding primary inductor not coupled to the selected, with the non-corresponding primary inductor at a predetermined frequency.

9. The wireless communication system according to claim 8,

wherein the predetermined frequency is a self-resonance frequency of the non-corresponding primary inductor.

10. The wireless communication system according to claim 8,

wherein the predetermined frequency is a frequency of an interference wave input to the selected low noise amplifier.

11. The wireless communication system according to claim 3,

wherein the received signals of different frequency bands are selectively input between differential input nodes of the low noise amplifiers.

12. The wireless communication system according to claim 1, further comprising:

a low noise amplifier which includes differential input nodes coupled to the secondary inductor and differential output nodes coupled to the demodulator.

13. The wireless communication system according to claim 12,

wherein the low noise amplifier includes a gate ground amplifier circuit having one end coupled to a load inductor and other end coupled to the secondary inductor.

14. The wireless communication system according to claim 13, further comprising:

a plurality of first variable capacitance elements which respectively correspond to the first primary inductors, and are parallelly coupled to their corresponding primary inductors, and

a second variable capacitance element which is parallelly coupled to the load inductor.

15. The wireless communication system according to claim 14,

wherein the semiconductor device further includes a control unit,

wherein, when a received signal is input to one of the primary inductors, the control unit is configured to set a capacitance value of a corresponding first variable element, in a manner that a parallel resonance circuit is configured with the primary inductor with the received signal input thereto and the corresponding first variable capacitance element at a frequency of the received signal, and to set a capacitance value of the second variable capacitance element, in a manner that a parallel resonance circuit is configured with the load inductor and the second variable capacitance element at the frequency of the received signal.