Coupling nanoscale emitters via optical antennas enables comprehensive control of photon emission in terms of intensity, directivity and polarization. In this work we report highly directional emission of circularly polarized photons from quantum dots coupled to a spiral optical antenna. The structural chirality of the spiral antenna imprints spin state to the emitted photons. Experimental resu...

Multiple-input multiple-output (MIMO) antenna systems employ spatial multiplexing to increase spectral efficiency or transmit diversity to improve link reliability. The performance of these signaling strategies is highly dependent on MIMO channel characteristics, which, in turn, depend on antenna height and spacing and richness of scattering. In practice, large antenna spacings are often requir...

This paper presents measurement results at 2.3 GHz for multiple-input multiple-output (MIMO) systems applying multiple polarized antenna arrays and single polarized uniform linear arrays (ULAs). The measurements were taken indoor in two different buildings, outdoor between a base station on the rooftop and a mobile station in a car, as well as between two mobile stations in two cars (C2C). Meas...

A compact reconfigurable four-feeding microstrip antenna with polarization diversity is presented in this paper. With four triangle-shaped elements as the radiation patch, the proposed antenna can achieve good impedance match for linear polarization (LP), left-hand circular polarization (LHCP) and right-hand circular polarization (RHCP). A four-way power divider made by three Wilkinson power di...

Large channel capacity is achieved by MIMO (Multiple-Input Multiple-Output) technology with multi-antenna at the transmitting and receiving side [1]. Many studies to maximize the MIMO channel capacity have been performed, and measurements show that channel capacity is enhanced by directional antennas [2] and multi-polarization [3] in indoor environment. Various MIMO antennas with pattern and po...

A set of hybrid microstrip patch and semi-circular cavity antennas is introduced. The semi-circular cavity is implemented using Half-mode Substrate Integrated Waveguide (HMSIW) technique. Different shapes of patch include rectangular, semi-circular and equilateral triangular are excited using proximity effect by the circular SIW cavity at its TM010 mode of operation. The whole structures have b...

An effective development of a dual composite right/lefthanded (D-CRLH) leaky-wave (LW) structure for dual-polarized antenna application is presented. The dual-polarized antenna consists of a two-section 3-dB rat-race hybrid and two symmetrical substrate integrated waveguide lines. Each of the waveguide lines is periodically loaded with 15 transverse slots and 15 longitudinal slots. The dualpola...

A novel monopole asymmetric fractal micro strip antenna is designed and analyzed in this paper. The proposed Koch fractal monopole antenna is resonating at triband with circular polarization operation. Five diff structures without slot (basic model), single slot (Iteration 1), double slotted (Iteration 2), triple slotted (Iteration 3), and optimized fractal slot (Iteration 4) are studied for ci...

Electromagnetic band-gap (EBG) structures exhibit unique electromagnetic properties that have led to a wide range of applications in antenna and propagation fields [1], [2]. There are two major advantages associated with EBG ground planes. First, such structures exhibit the possibility of creating a perfect magnetic conductor (PMC) because of their in-phase reflection phase characteristics. Thi...

This paper presents the design of a broadband circular polarization truncated horn antenna with single feed. It does not require any complex feeding structure and uses only a coaxial feed extended with a simple electric field coupling probe. The corners of the horn are truncated to generate circular polarization modes, and a broad axial ratio bandwidth which is insensitive to the probe feed dim...