关于微带带宽窄及其影响因素的阐述
Generally, microstrip antenna is like a RLC circuit with high Q because of its thin substrate. Variation of bandwidth versus height of the substrate has been shown. Bandwidth increases using thicker substrates, but thick substrate has impedance matching problem because of its big inductance. On the other hand, by increasing the dielectric constant bandwidth decrease. Although thick dielectric with little permeability has larger bandwidth, it is still a few percentages. Patch shaping (changing the geometry of patch) also effects bandwidth of antenna. For instant, triangular antenna has bigger bandwidth than rectangular antenna, or wide rectangular antenna has bigger bandwidth than narrow one. Bowtie patch antenna is also bigger bandwidth compared to similar rectangular antenna.
Unlike the most of bandwidth enhancement methods, slot loading saves major advantage of microstrip antennas, low profile. Slots which are loaded at the edge of the patch increase the bandwidth of the antenna by exciting new modes or complete excitation of existing modes[5]. In contrast, the slots which are loaded to near the antenna excitation acts as inductance compensator[6].
理解圆极化
双谐振器天线
A multi-resonator microstrip-fed patch antenna for broadband dual-band operation
- This antenna uses two resonators separeted by an U-shaped air gap.
