US 12,586,880 B2 · Broadband switch for 3T and 7T magnetic resonance imaging

Abstract

A hybrid microstripline transmit/receive switch and methods for use in magnetic resonance imaging of X-atomic nuclei at 3T and 7T magnetic field strengths. A first and second dielectric substrate each include a broadband hybrid magnetic coupler formed on the top side and a ground plane formed on the bottom side. An RF electrical signal is input to a first port and a second port transmits the signal when a first pin diode and a second pin diode are forward biased. A third port is isolated and a fourth port receives signals when the first and second pin diodes are reversed biased. Tuning capacitors are connected to the ports. The T/R switch is configured to operate in broadband frequency ranges of about 25 MHz to about 55 MH, of about 61 MHz to about 128 MHz, and of about 250 MHz to about 317 MHz.

A broadband hybrid magnetic coupler for magnetic resonance imaging (MRI) of atomic nuclei, comprising:

a dielectric substrate having a top side and a bottom side, a first edge opposite to a second edge, a third edge opposite to a fourth edge, wherein a first central axis of the dielectric substrate is configured to bisect the first edge and the second edge and to extend from the first edge to the second edge and wherein a second central axis of the dielectric substrate is configured to bisect the third edge and the fourth edge and to extend from the third edge to the fourth edge;
a first port, a second port, a third port and a fourth port, wherein each port is configured to connect to a sub-miniature radio frequency (RF) connector located on the bottom side of the dielectric substrate;
a multi-bended microstripline formed on the dielectric substrate, wherein the multi-bended microstripline has six branches, including:
a first branch having a multi-bended structure extending between first port and the fourth port and between the third edge and the first central axis, wherein the multi-bended structure of the first branch includes a first straight leg connected to the first port, a second straight leg connected to the fourth port and a three lobed loop connected between the first straight leg and the second straight leg, wherein the three lobed loop is centered about the second central axis;
a second branch extending between the first port and the second port, the second branch comprising a first straight leg connected to the first port, a second straight leg, a first four lobed loop connected between the first straight leg and the second straight leg, a third straight leg connected to the second port, and a second four lobed loop connected between the second straight leg and the third straight leg;
a third branch extending between the second port and the third port, wherein the third branch is a mirror image of the first branch;
a fourth branch extending between the third port and the fourth port, wherein the fourth branch is a mirror image of the second branch;
a phase inverter located at an intersection of the first central axis and the second central axis;
a fifth branch located between an intersection of the second branch with the first central axis and the phase inverter, the fifth branch comprising a straight leg connected to the second branch and a single lobed loop connected to the phase inverter, wherein the single lobed loop extends from the first central axis towards the fourth edge, and wherein the single lobed loop is centered about the second central axis;
and
a sixth branch located between an intersection of the fourth branch with the first central axis and the phase inverter, the sixth branch comprising a straight leg connected to the fourth branch and a single lobed loop connected to the phase inverter, wherein the single lobed loop extends from the first central axis towards the third edge, and wherein the single lobed loop is centered about the second central axis,
wherein each of the microstripline of the first branch and the microstripline of the third branch have a width Wa;
wherein each of the microstriplines of the second branch, the fourth branch, the fifth branch and the sixth branch have a width Wb, where the width Wb equals about seven times the width Wa,
wherein the multi-bended microstripline is configured to receive electrical signals at the first port and resonate the electrical signals at frequencies of about 95 MHz and about 285 MHz at the second port and at the fourth port, wherein the frequencies at the fourth port are orthogonal to the frequencies at the second port, and wherein the wherein the third port is isolated.

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Broadband switch for 3T and 7T magnetic resonance imaging

Life of this patent

Broadband switch for 3T and 7T magnetic resonance imaging

Life of this patent

Abstract

Claims20