Dual circular polarization waveguide system
First Claim
1. A dual probe waveguide structure for use in a LNB (low noise block) for receiving a left (L) and a right (R) circularly polarised electromagnetic radiation signal and for converting the circularly polarised signals into linearly polarised signals, the waveguide structure comprisinga waveguide housing of a substantially symmetrical cross section, said waveguide housing having a front aperture and a rear waveguide wall, wherein the waveguide wall is provided by a ground plane of a circuit board disposed at the end of the waveguide, a septum disposed within the housing and coupled to the rear waveguide wall and the housing to separate the waveguide into two waveguide compartments, one compartment for receiving and converting the left circular polarisation signal into a first linearly polarised signal and the other compartment for receiving and converting the right circular polarised signal into a second linearly polarised signal orthogonal to the first linearly polarised signal, a first probe extending into said first waveguide compartment from the rear waveguide wall and a second probe extending into the second rear waveguide compartment from the second waveguide wall the first and second probes each having a free end, the probes being oriented and arranged such that the free ends of the probes are disposed in proximity to the waveguide wall or septum in each respective compartment such that the probes capacitively couple into the magnetic field of the primary or fundamental waveguide mode in the waveguide compartment.
11 Assignments
0 Petitions
Accused Products
Abstract
A dual circular polarization waveguide (24) is described which has a septum (36) which divides the waveguide (24) into two separate compartments (38, 40) each with a probe (30A, 30B) passing through the end wall (32) of the waveguide (24) into the compartment (38, 40) to detect respective signals in each of the compartments (38, 40). The septum (36) is proportioned and dimensioned to convert the left and right circularly polarized signals, into substantially linearly polarized signals as the signals pass along the waveguide (24) past the septum (36) so as by the time the signals reach the probes (30A, 30B) they are linearly polarized. The probes (30A, 30B) which pass through the rear wall (32) of the waveguide (24) are oriented such that they couple into the magnetic field of the primary or fundamental waveguide mode. These probes (31A, 30B) do not require to be orthogonal to each other but each probe (31A, 30B ) has a free end disposed in proximity to a waveguide wall or the septum (36) within a respective compartment (38, 40) so that the probe (30A, 30B) is capacitively coupled to the waveguide wall or septum (36) to allow the probe (30A, 30B) to couple into the respective magnetic field in the compartment (38, 40).
-
Citations
15 Claims
-
1. A dual probe waveguide structure for use in a LNB (low noise block) for receiving a left (L) and a right (R) circularly polarised electromagnetic radiation signal and for converting the circularly polarised signals into linearly polarised signals, the waveguide structure comprising
a waveguide housing of a substantially symmetrical cross section, said waveguide housing having a front aperture and a rear waveguide wall, wherein the waveguide wall is provided by a ground plane of a circuit board disposed at the end of the waveguide, a septum disposed within the housing and coupled to the rear waveguide wall and the housing to separate the waveguide into two waveguide compartments, one compartment for receiving and converting the left circular polarisation signal into a first linearly polarised signal and the other compartment for receiving and converting the right circular polarised signal into a second linearly polarised signal orthogonal to the first linearly polarised signal, a first probe extending into said first waveguide compartment from the rear waveguide wall and a second probe extending into the second rear waveguide compartment from the second waveguide wall the first and second probes each having a free end, the probes being oriented and arranged such that the free ends of the probes are disposed in proximity to the waveguide wall or septum in each respective compartment such that the probes capacitively couple into the magnetic field of the primary or fundamental waveguide mode in the waveguide compartment.
Specification