Differential pair impedance matching for a printed circuit board
A printed circuit board (PCB), such as an antenna backplane, including a first conductor and a second conductor forming a differential pair, a first junction and a second junction connected to the first conductor and the second conductor, respectively, and a first impedance matching stub and a second impedance matching stub connected to the first conductor and the second conductor, respectively. The differential pair has a first impedance, the first junction and the second junction have a second impedance, and the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance. The PCB may have a connector that has differential pins joined to the first and second junctions, and the first impedance matching stub and the second impedance matching stub match an impedance of the junctions, pins, and a connector to the first impedance.
1 . A printed circuit board (PCB) comprising:
a differential pair including a first conductor and a second conductor;
a first junction and a second junction connected to the first conductor and the second conductor, respectively;
a first impedance matching tuning stub and a second impedance matching tuning stub connected to the first junction and to the second junction, respectively, wherein the first impedance matching tuning stub includes dual impedance matching tuning stubs; and
a connector including first and second differential pins, wherein the first and second differential pins are electrically coupled to the first and second junctions, respectively.
2 . The PCB of claim 1 , wherein the differential pair has a first impedance, the first junction and the second junction have a second impedance, and the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
3 . The PCB of claim 1 , wherein the differential pair has a first impedance, the first junction and the second junction have a second impedance, the first impedance matching stub has a first length and a first shape, the second impedance matching stub has the first length and the first shape, and at least one of the first length or the first shape being such that the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
4 . The PCB of claim 1 , wherein the differential pair has a first impedance, the first junction and the second junction have a second impedance, the first impedance matching stub has a first length and a first shape, the second impedance matching stub has second length and a second shape, and at least one of the first length, the first shape, the second length, or the second shape match the second impedance to the first impedance.
5 . The PCB of claim 1 , wherein at least one of the first impedance matching stub or the second impedance matching stub is either a stripline or a microstrip.
6 . The PCB of claim 1 , wherein the PCB has a first side and a second side separated by a non-conductive substrate, the first side having a ground plane, and the differential pair of conductors, the first impedance matching stub, the second impedance matching stub, the first junction, and the second junction, are on the second side.
7 . The PCB of claim 1 , wherein the PCB is a multilayer printed circuit board, and the first impedance matching stub and the second impedance matching stub are on an internal layer of the PCB.
8 . The PCB of claim 1 , wherein the second impedance matching tuning stub includes dual impedance matching tuning stubs.
9 . A printed circuit board (PCB) comprising:
a differential pair of conductors, the differential pair having a first conductor and a second conductor;
a first pad and a second pad connected to the first conductor and the second conductor, respectively;
a first impedance matching stub and a second impedance matching stub connected to the first pad and the second pad, respectively, wherein the first impedance matching tuning stub includes dual impedance matching tuning stubs; and
a connector mounted on the PCB, the connector having a differential pair of pins, the differential pair of pins being connected to the first pad and the second pad, wherein the differential pair has a first impedance, the first and second pad, the connector, and the differential pair of pins present a second impedance, and the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
10 . The PCB of claim 9 , wherein the distal end of the first impedance matching stub and the distal end of the second impedance matching stub are open-circuited.
11 . The PCB of claim 9 , wherein the first impedance matching stub has a first length, the second impedance matching stub has the first length, and the first length being such that the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
12 . The PCB of claim 9 , wherein the first impedance matching stub has a first length, the second impedance matching stub has a second, different length, and the first length and the second length being such that the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
13 . The PCB of claim 9 , wherein the first impedance matching stub has a first shape, the second impedance matching stub has the first shape, and the first shape being such that the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
14 . The PCB of claim 9 , wherein the first impedance matching stub has a first shape, the second impedance matching stub has a second, different shape, and the first shape and the second shape are such that the first impedance matching stub and the second impedance matching stub match the second impedance to the first impedance.
15 . The PCB of claim 9 , wherein the second impedance matching tuning stub includes dual impedance matching tuning stubs.