Multiband Microstrip Antenna Research Articles

Multiband Rectangular Microstrip Antennas

The dual-band microstrip antennas (MSAs) are realized by placing the stub on the edges of the patch or by cutting a slot at an appropriate position inside the patch. The multiband MSAs are realized by using the combination of the slot and stub. In this paper, by cutting a rectangular slot on the radiating edge and half U-slot on the nonradiating edge of a rectangular MSA, a dual- and triple-band rectangular MSA are proposed. These slots are of nearly quarter wave in length and by changing their lengths, tuning of the frequencies is realized. Also, the multiport network models for these multiband MSAs are proposed, which helps in understanding the mode distributions at slot and patch frequencies. To realize the higher gain, the suspended configurations of these multiband antennas are also proposed. A good agreement is obtained between the simulated, multiport network model, and measured results.

Reconfigurable Loaded Planar Inverted-F Antenna Using Varactor Diodes

This letter presents a compact reconfigurable multiband microstrip antenna. The multiplicity of bands is achieved by the use of concentric external metallic semirings around a central internal semicircular microstrip patch. These are all shorted to the ground plane via a vertical metallic wall through the common diametric plane, thereby adopting the concept of the planar inverted-F antenna (PIFA) for size reduction and thus compactness. The operation frequencies are tuned by varactor diodes placed between the inner semicircular patch and the outer half-rings. In addition to tunability, the overall bandwidth may also be widened by combining the tunable range. Theoretical simulations and measurements of manufactured prototypes agree well with each other.

Small multi-band microstrip antenna for wireless applications

A simple microstrip line fed antenna with thin substrate is proposed in this letter for multi-band wireless applications. The multi-band characteristic was achieved by overlapping an annular slot antenna with two concentric fan shaped patches. The antenna demonstrates three wide impedance bandwidths (VSWR ≤ 2) of 36.3, 63.4 and 25.5% with stable polarization and radiation characteristics.

MUTUAL COUPLING REDUCTION USING DUMBBELL DEFECTED GROUND STRUCTURE FOR MULTIBAND MICROSTRIP ANTENNA ARRAY

A novel design of multiband microstrip antenna array with dumbbell shape defected ground structure (DGS) is presented. The DGS is inserted into the ground plane between the two elements of the antenna array in order to suppress mutual coupling. Both simulation and measurement results verifled that the DGS improved the radiation properties of the antenna array. Measurement results of the DGS antenna showed mutual coupling reduction of maximum 5dB and gain enhancement to 3dB.

Stub loaded multi-band slotted rectangular microstrip antennas

The multi-band rectangular microstrip antennas (MSAs) realised by placing an open-circuit stub on the edges of the patch and by cutting resonant slots inside the patch are proposed. The multi-port network models for these multi-band rectangular MSAs are also proposed which helps in analysing the voltage distributions at various frequencies. Also the multi-band frequency response of these configurations is experimentally verified.

New Multi-Band Microstrip Antenna Design for Wireless Communications

This paper presents a new approach for the design of a multi-wideband microstrip-patch antenna. The radiating elements in this antenna are composed of rectangular slots following a Chebyshev distribution of order 10 around a center rectangular slot, and an additional triangular slot. These slots are engraved in the rectangular and triangular patch, joined together in one structure, and fed by one probe feed. A sample antenna was analyzed, simulated, fabricated, and tested. There was good agreement between the computed and test results. The new antenna can be used for several applications, especially in the GSM domain, and for Wi-Fi, Bluetooth, and several other applications, as detailed in this paper.