Radio frequency amplifying device and magnetic resonance imaging apparatus

Patent metadata

Field	Value
Publication number	US-11585879-B2
Application number	US-202017002888-A
Country	US
Kind code	B2
Filing date	Aug 26, 2020
Priority date	Sep 4, 2019
Publication date	Feb 21, 2023
Grant date	Feb 21, 2023

Abstract

A radio frequency amplifying device according to an embodiment includes load impedance calculating circuitry and controlling circuitry. The load impedance calculating circuitry is configured to calculate a load impedance on the basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry. The controlling circuitry is configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.

First claim

What is claimed is:

1. A radio frequency amplifying device comprising:
load impedance calculating circuitry configured to calculate a load impedance on a basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry; and
controlling circuitry configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.

2. The radio frequency amplifying device according to claim 1 , wherein the controlling circuitry further controls an operating point of the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.

3. The radio frequency amplifying device according to claim 2 , wherein the controlling circuitry controls the operating point of the radio frequency amplifying circuitry, by changing direct current voltage supplied to the radio frequency amplifying circuitry.

4. The radio frequency amplifying device according to claim 3 , wherein the controlling circuitry adjusts the gain and the phase of the signal to be input to the radio frequency amplifying circuitry and the direct current voltage supplied to the radio frequency amplifying circuitry, on a basis of adjustment value information indicating a correspondence relationship among a set made up of the load impedance and the signal, an adjustment value for the gain, an adjustment value for the phase, and an adjustment value for the direct current voltage.

5. The radio frequency amplifying device according to claim 1 , wherein the controlling circuitry adjusts the gain of the signal by either attenuating or amplifying the signal to be input to the radio frequency amplifying circuitry.

6. A magnetic resonance imaging apparatus comprising a radio frequency amplifying device and a Radio Frequency (RF) coil, wherein
the radio frequency amplifying device includes:
load impedance calculating circuitry configured to calculate a load impedance on a basis of information about a voltage standing wave rate and a phase on an output side of radio frequency amplifying circuitry; and
controlling circuitry configured to adjust a gain and a phase of a signal to be input to the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry, and

the RF coil generates a radio frequency magnetic field on a basis of an output signal output from the radio frequency amplifying device.

7. The magnetic resonance imaging apparatus according to claim 6 , wherein the controlling circuitry further controls an operating point of the radio frequency amplifying circuitry, in accordance with the load impedance calculated by the load impedance calculating circuitry.

8. The magnetic resonance imaging apparatus according to claim 7 , wherein the controlling circuitry controls the operating point of the radio frequency amplifying circuitry, by changing direct current voltage supplied to the radio frequency amplifying circuitry.

9. The magnetic resonance imaging apparatus according to claim 8 , wherein the controlling circuitry adjusts the gain and the phase of the signal to be input to the radio frequency amplifying circuitry and the direct current voltage supplied to the radio frequency amplifying circuitry, on a basis of adjustment value information indicating a correspondence relationship among a set made up of the load impedance and the signal, an adjustment value for the gain, an adjustment value for the phase, and an adjustment value for the direct current voltage.

10. The magnetic resonance imaging apparatus according to claim 6 , wherein the controlling circuitry adjusts the gain of the signal, by either attenuating or amplifying the signal to be input to the radio frequency amplifying circuitry.

Assignees

• Canon Medical Systems Corp

Inventors

• Tanji Masaki
• Kawaguchi Susumu
• Tanaka Hajime

Classifications

• H03G3/3036

  in high-frequency amplifiers or in frequency-changers (H03G3/3052, H03G3/32, H03G3/34 take precedence) · CPC title

• H03F2200/207

  A hybrid coupler being used as power measuring circuit at the output of an amplifier circuit · CPC title

• H03F2200/471

  the voltage being sensed · CPC title

• H03F1/0233

  by using a signal derived from the output signal, e.g. bootstrapping the voltage supply · CPC title

• H03F2200/451

  the amplifier being a radio frequency amplifier · CPC title