Wang Guangming

Compact Dual-Band Zeroth-Order Resonance Antenna

A novel microstrip zeroth-order resonator (ZOR) antenna and its equivalent circuit model are exploited with two zeroth-order resonances. It is constructed based on a resonant-type composite right/left handed transmission line (CRLH TL) using a Wunderlich-shaped extended complementary single split ring resonator pair (W-ECSSRRP) and a series capacitive gap. The gap either can be utilized for double negative (DNG) ZOR antenna or be removed to engineer a simplified elision-negative ZOR (ENG) antenna. For verification, a DNG ZOR antenna sample is fabricated and measured. Numerical and experimental results agree well with each other, indicating that the omnidirectional radiations occur at two frequency bands which are accounted for by two shunt branches in the circuit model. The size of the antenna is 49% more compact than its previous counterpart. The superiority of W-ECSSRRP over CSSRRP lies in the lower fundamental resonance of the antenna by 38.2% and the introduction of a higher zeroth-order resonance.

Application of Ultra-Compact Single Negative Waveguide Metamaterials for a Low Mutual Coupling Patch Antenna Array Design

A novel ultra-compact single-negative waveguide metamaterial (WG-MTM) based on a complementary anti-parallel-spiral line (CAPAL) is proposed and investigated by circuit model analysis, electromagnetic simulation and extraction of the effective parameters. The cell is ultra-compact with dimensions of λ0/22.08 × λ0/22.08, which advances a step further toward homogenized concept. Two band-gaps attributing to the negative permeability and negative permittivity appear when the CAPAL-WG-MTM cells response to the time-varying perpendicular E-field and parallel H-field, and thus a high decoupling efficiency is obtained. Mutual coupling reduction of about 8.27 dB is realized by inserting 7 × 1 CAPSL-WG-MTM cells between two closely placed antenna elements with an edge-to-edge separation of only λ0/19.23. Moreover, the radiation characteristics are improved for both the patch element and the antenna array. A higher front-to-back ratio is obtained for the patch element and an increase of 0.64 dB for the gain of the antenna array by using the CAPAL-WG-MTM structure.

Compact tri-band rat-race coupler based on novel metamaterial transmission line

A compact tri-band rat-race coupler is proposed in this paper by using a novel metamaterial (MTM) transmission line (TL). The novel MTM TL has two frequency points with - 90-degree shift and one frequency points with +90-degree shift in the passbands as well as the nonlinear dispersion. Taking advantage of these features, a compact tri-band rat-race coupler operating at 2.20 GHz, 3.38 GHz and 7.30 GHz is designed, fabricated and measured. The measured and simulated results are in good agreement, indicating good performances for in-phase operation and anti-phase operation at the three operating bands. Moreover, compared with the conventional rat-race coupler, this one not only realizes triple-band operation, but also realizes 64.6% area reduction.

Enhancement of Organic Electroluminescent Intensity by Doping Hole-Property Polymers

Organic electroluminescent (EL) diodes with one-layer poly(3-octylthiophene) (P3OT) and P3OT doped with poly(N-vinylcarbazole) (PVK) (P3OT/PVK) as EL emitting layer sandwiched between indium/tin oxide (ITO) and aluminium electrodes have been fabricated by spin coating onto ITO respectively. The P3OT/PVK EL diode starts to emit red-orange light at 5 V in our experiment, the luminance and the current for the P3OT/PVK EL diode at bias voltage was compared with those for the only P3OT EL diode, indicating that the PVK dopant has power over the P3OT electroluminescence.