A coupled-line rat-race coupler includes four ports and four coupled-lines each composed of two metal lines. Two of the ports are respectively connected with the front ends of the two lines of the first coupled-line, and the other two ports are respectively connected with the front ends of the two lines of the second coupled-line. The two lines of the third coupled-line are short circuited and respectively connected with the back end of one line of the first coupled-line on one side and with the back end of one line of the second coupled-line on the other side. In the fourth coupled-line, one line is open at one end and short circuited at the other end with the other line, which is connected with one line of the first coupled-line and one line of the second coupled-line. The coupled-line rat-race coupler is characterized with smooth and stable output phase.

A phase shifter device is disclosed and comprises a continuous transmission line on a substrate, and a plurality of ports coupled to the continuous transmission line and spaced apart from each other around the continuous transmission line. The plurality of ports comprises a first port, a second port, a third port, a fourth port, and a fifth port. A radio frequency (RF) switch is operative to connect either the first port or the fifth port to a main RF line that is coupled to one or more antennas. The second port is located between the first port and the third port, and the fourth port is located between the fifth port and the third port. In an alternative embodiment, the phase shifter device is combined with a circular polarization quadrature divider.

The present disclosure provides systems and methods associated with mode conversion for electromagnetic field modification. A mode converting structure (holographic metamaterial) is formed with a distribution of dielectric constants chosen to convert an electromagnetic radiation pattern from a first mode to a second mode to attain a target electromagnetic radiation pattern that is different from the input electromagnetic radiation pattern. A solution to a holographic equation provides a sufficiently accurate approximation of a distribution of dielectric constants that can be used to form a mode converting device for use with one or more transmission lines, such as waveguides. One or more optimization algorithms can be used to improve the efficiency of the mode conversion.

A radar system (200, 200a) and a method of operating a radar system are described, the radar system (200, 200a) comprising: a plurality of ICs (210, 220), each IC (210, 220) comprising: a respective LO output (212, 222) for selectively outputting a respective LO signal, and a respective LO input (214, 224); and a coupling device (230, 330), the coupling device (230, 330) comprising: a plurality of inputs (232, 234; 341, 342, 351, 352), each input being coupled to the LO output (212, 222) of a respective IC (200, 200a), and a plurality of outputs (236, 238; 363, 364, 373, 374), each output being coupled to the LO input (212, 222) of a respective IC (214, 224); wherein the coupling device (230, 330) is configured such that a LO signal arriving at any one of said plurality of inputs (232, 234; 341, 342, 351, 352) is distributed to each of said plurality of outputs (236, 238; 363, 364, 373, 374). The coupling device (230, 330) may comprise at least one directional coupler.

An annual directional coupler having at least three taps, which are each arranged relative to one another around routes having a wavelength difference of of a wave guide wavelength, includes in particular at least two branch lines, wherein a first branch line has at least three taps and wherein the at least second branch line does not have any taps and is supplemented by an additional route corresponding to the wave guide wavelength.

A rat-race balun includes a transmission line loop and 4 input-output ports P.sub.1, P.sub.2, P.sub.3, P.sub.4 connected to the transmission line loop, the balun being designed to receive a first signal on the port P.sub.1, and to divide the first signal into a second signal that is delivered to the port P.sub.2 and a third signal that is delivered to the port P.sub.4, the second signal and the third signal being in phase opposition with one another, the balun wherein the balun is kidney-shaped and the ports P.sub.2, P.sub.4 each comprise at least a first section connected to the transmission line, the first section of the port P.sub.2 being parallel to the first section of the port P.sub.4.

A structure can include a first element and a carrier bonded to the first element along an interface. A waveguide can be defined at least in part along the interface between the first element and the carrier. The waveguide can comprise an effectively closed metallic channel and a dielectric material within the effectively closed metallic channel, as viewed from a side cross-section of the structure. Various millimeter-wave or sub-terahertz components or circuit structures can also be created based on the waveguide structures disclosed herein.

Ultra-Wideband (UWB) technology is a wireless technology for the transmission of large amounts of digital data as modulated coded impulses over a very wide frequency spectrum with very low power over a short distance. However, to support their deployment in a wide range of applications it would be beneficial to provide solutions which: exploit multiple directive antennas oriented in different directions to ensure spatial filtering of undesired signals and increase signal strength; exploit dynamic configuration of the multi-pulse bundles employed to transmit the bits/symbols within the packets to enhance link quality of service; exploit dynamic configuration of the band or bands which the transmitter operates upon; and exploit antenna sub-systems providing omnidirectional radiation patterns with implementations offering filtering and balun functions with small footprint and low cost.

A directional coupler includes: a first waffle-iron ridge waveguide extending from one end to other end; a second waffle-iron ridge waveguide extending from one end to the other end; a first bypass waveguide connecting a first site of the first waffle-iron ridge waveguide and a first site of the second waffle-iron ridge waveguide; and a second bypass waveguide connecting a second site of the first waffle-iron ridge waveguide and a second site of the second waffle-iron ridge waveguide.

The present disclosure provides systems and methods associated with mode conversion for electromagnetic field modification. A mode converting structure (holographic metamaterial) is formed with a distribution of dielectric constants chosen to convert an electromagnetic radiation pattern from a first mode to a second mode to attain a target electromagnetic radiation pattern that is different from the input electromagnetic radiation pattern. A solution to a holographic equation provides a sufficiently accurate approximation of a distribution of dielectric constants that can be used to form a mode converting device for use with one or more transmission lines, such as waveguides. One or more optimization algorithms can be used to improve the efficiency of the mode conversion.