Ground planes as small as 4x4 square patches are used without shorting vias. The planar size of the artificial ground plane is about 0.837lambdaox0.837lambdao. To have a physically robust structure, each antenna is printed on a dielectric slab, which is placed over the artificial ground plane....
A spiral, helical antenna is configured to produce a generally circular polarized radiation pattern covering a range of frequencies, over a ground plane. The antenna is comprised of a spring-like spiral conductor that may be held in compression by a size and shape regulating outer nonconductive ...
Fig. 3. CSA over the ground with the virtual apex of the antenna placed at the air/ground interface. component (copolarized component) of the electric field inci- dent from the forward direction, while the right-handed circu- larly component (cross-polarized component) passes by mainly ...
In this letter, we propose a compact spiral stripline-loaded monopole antenna on a vertical ground plane. The measured results show that the antenna has a fractional bandwidth of 12.1% for a voltage standing wave ratio (VSWR) less than 2 at the center frequency of 1.10 GHz, as well as a...
Both of these surveys incorporated single antenna measurements (NRO 45 m measurements for OVRO, NRAO 12 Meter Telescope measurements for BIMA) into their interferometer data to provide a complete sample of the CO emission in each galaxy. These surveys have made it possible to compare the detailed...
A novel and feasible solution to generate plane spiral orbital angular momentum (PSOAM) vortex beam is proposed in this paper. The general principle of generating PSOAM in circular antenna array (CAA) is deduced, and verified by the simulation of the dip
An ultra-wideband four-arm spiral-helix antenna with simple beamformer is developed to have simultaneously good performance in time and frequency. Two microstrip feeds printed on the opposite side of the spiral with impedance following Klopfenstein taper are employed to eliminate the need for 180<for...
A planar antenna comprising a spiral conductive surface comprising an inner spiral segment and an outer spiral segment. A shorting leg for connection to a ground plane an
An antenna comprises a first antenna element, which has a first helix, and a second antenna element, which has a second helix. The first and the second antenna elements each have a
An element antenna for use with a plurality of similar element antennas in an array. The element antenna receives and reradiates circular polarized electromagnetic energy such that the reradiated ener