Before the emergence of ultra-wideband (UWB) radios, widely used wireless communications were based on sinusoidal carriers, and impulse technologies were employed only in specific applications (e.g. radar). In 2002, the Federal Communication Commission (FCC) allowed unlicensed operation between 3.1–10.6 GHz for UWB communication, using a wideband signal format with a low EIRP level (−41.3dBm/MHz). UWB communication systems then emerged as an alternative to narrowband systems and significant effort in this area has been invested at the regulatory, commercial, and research levels.

IEEE Transactions on Microwave Theory and Techniques and Antennas and Propagation Announce a Joint Special Issue on Ultra-Wideband (UWB) Technology

Aspects of the subject disclosure may include, for example, receiving, by a feed point of a dielectric antenna, electromagnetic waves from a dielectric core coupled to the feed point without an electrical return path, where at least a portion of the dielectric antenna comprises a conductive surface, directing, by the feed point, the electromagnetic waves to a proximal portion of the dielectric antenna, and radiating, via an aperture of the dielectric antenna, a wireless signal responsive to the electromagnetic waves being received at the aperture. Other embodiments are disclosed.

Method and apparatus for coupling an antenna to a device

Substrate integrated waveguide (SIW) technology provides an attractive solution to the integration of planar and nonplanar circuits by using a planar circuit fabrication process. However, it is usually difficult to implement the negative coupling structure required for the design of compact canonical folded elliptic or quasi-elliptic cross-coupled bandpass filter on the basis of a single-layer SIW. In this paper, a special planar negative coupling scheme including a magnetic coupling post-wall iris and a balanced microstrip line with a pair of metallic via-holes is studied in detail. Two -band fourth-degree cross-coupled bandpass filters without and with source-load coupling using the negative coupling structures are then proposed and designed. The two novel SIW filters having the same center frequency of 20.5 GHz and respective passband width of 700 and 800 MHz are implemented on a single-layer Rogers RT/Duroid 5880 substrate with thickness of 0.508 mm. Measured results of those filters, which exhibit a high selectivity, and a minimum in-band insertion loss of approximately 0.9 and 1.0 dB, respectively, agree well with simulated results.

Substrate Integrated Waveguide Cross-Coupled Filter With Negative Coupling Structure

A distributed antenna and backhaul system provide network connectivity for a small cell deployment. Rather than building new structures, and installing additional fiber and cable, embodiments described herein disclose using high-bandwidth, millimeter-wave communications and existing power line infrastructure. Above ground backhaul connections via power lines and line-of-sight millimeter-wave band signals as well as underground backhaul connections via buried electrical conduits can provide connectivity to the distributed base stations. An overhead millimeter-wave system can also be used to provide backhaul connectivity. Modules can be placed onto existing infrastructure, such as streetlights and utility poles, and the modules can contain base stations and antennas to transmit the millimeter-waves to and from other modules.

Backhaul link for distributed antenna system

A distributed antenna system is provided that frequency shifts the output of one or more microcells to a 60 GHz or higher frequency range for transmission to a set of distributed antennas. The cellular band outputs of these microcell base station devices are used to modulate a 60 GHz (or higher) carrier wave, yielding a group of subcarriers on the 60 GHz carrier wave. This group will then be transmitted in the air via analog microwave RF unit, after which it can be repeated or radiated to the surrounding area. The repeaters amplify the signal and resend it on the air again toward the next repeater. In places where a microcell is required, the 60 GHz signal is shifted in frequency back to its original frequency (e.g., the 1.9 GHz cellular band) and radiated locally to nearby mobile devices.

Remote distributed antenna system

A novel `short-slot' coupler design variant is introduced to provide high performance over a substantial increased operating bandwidth compared with the state-of-the-art. It is based on an optimised overmoded coupling region that is associated with appropriate waveguide transformers to match the dedicated standard rectangular waveguide ports. The established single acting structure is supported by the design capability of effective EM CAD methods and facilitates low cost production by standard milling techniques. Theoretical and experimental results of 3dB couplers at 26GHz - covering a frequency band of 25% with a coupling variation of less than ±0.25dB - and at 30GHz covering 20% bandwidth (with a coupling variation of less than ±0.1dB) prove the validity of the approach.

Improved Narrow-Wall Short Slot Coupler Design Exhibiting Significant Increased Bandwidth and Low Cost Production

A novel TE113 dual mode cavity filter design is introduced that provides remote controlled reallocation of center frequency and bandwidth. The reconfiguration principle1 considers both end-walls of the cavities to be independently moveable along the cavity axes. This allows convenient control of cavity resonance frequencies (cavity length) and filter couplings (i.e., field strength in front of the coupling means inside the cavity). Higher order filters are realized by side-wall cavity arrangements using synchronous movement of all cavity end-walls with only two actuation units. EM analyses and measured results of a 2-order filter design at 11.2GHz prove the feasibility of the new solution.

Novel remote controlled dual mode filter providing flexible re-allocation of center frequency and bandwidth

A novel waveguide T-junction is shown to provide the basic building block of a very compact OMT design. It is formed by a short circuited common circular (or square) waveguide section exhibiting two rectangular waveguide ports at the short circuit situated at opposed side walls — one with an E- and the other with an H-plane alignment. Thus the orthogonal modes (polarizations) of the common waveguide are coupled by different field components at the side wall ports, i.e., the E-plane waveguide port couples the H x -fields of the 1st polarization (TE 11s /TE 01 ) while the H-plane port serves the H z -fields of the orthogonal one (TE 11c /TE 10 ). High isolation between the orthogonal polarized signals is obtained due to the symmetry and the port alignment of the structure. The implementation of appropriate discontinuities within the T-junction allows the realization of a single-acting OMT solution with high performance properties. The approach is verified by a realized OMT design at 26GHz that is made from a single block by CNC machining

http://ieeexplore.ieee.org/iel5/6088932/6101646/06101784.pdf

Compact T-junction orthomode transducer facilitates easy integration and low cost production

The paper presents a new class of compact in-line pseudo-elliptic filters which are based on combining waveguide cavities and resonant irises. Two different configurations, which allow precise control of the direct couplings between the different resonator types, are introduced. Two different 3-pole filters have been designed to demonstrate the feasibility of the principle. The first filter combines a resonant iris and two TE/sub 101/ mode cavities while the second one utilizes two TM/sub 110/ mode cavities and one resonant iris. The latter has been realized and its response measured. Excellent agreement between computed and measured responses is achieved.

/pdf/mixed-resonance-compact-in-line-pseudo-elliptic-filters-4vj6u5wtvp.pdf

Mixed-resonance compact in-line pseudo-elliptic filters

A unique high Q dual-mode cavity filter design for remote controlled reallocation of center frequency and bandwidth is introduced. It builds on a sidewall arrangement of cylindrical cavities that allows independent movement of the end-walls at both sides. The dual mode cavities are coupled as doublets for the realization of transmission zeros. All cavity end-walls situated at the same side are synchronously adjusted, i.e., the reconfiguration of the overall filter requires only two actuation drives1. This solution has been validated by 2-order and 5-order filter designs implemented with TE 113 dual-mode cavities at 11.2GHz. The results of the EM-analysis of the 5-order filter and the measured remote controlled hardware of the 2-order design demonstrate the capability of center frequency and bandwidth reallocation.

Uwe Rosenberg

Papers

Improved Narrow-Wall Short Slot Coupler Design Exhibiting Significant Increased Bandwidth and Low Cost Production

Novel remote controlled dual mode filter providing flexible re-allocation of center frequency and bandwidth

Compact T-junction orthomode transducer facilitates easy integration and low cost production

Mixed-resonance compact in-line pseudo-elliptic filters

Reconfigurable doublet dual-mode cavity filter designs providing remote controlled center frequency and bandwidth re-allocation