Sang-Hyuk Wi

Wideband Microstrip Patch Antenna With U-Shaped Parasitic Elements

A wideband U-shaped parasitic patch antenna is proposed. Two parasitic elements are incorporated into the radiating edges of a rectangular patch whose length and width are lambdag/2 and lambdag/4, respectively, in order to achieve wide bandwidth with relatively small size. Coupling between the main patch and U-shaped parasitic patches is realized by either horizontal or vertical gaps. These gaps are found to be the main factors of the wideband impedance matching. The proposed antenna is designed and fabricated on a small size ground plane (25 mmtimes30 mm) for application of compact transceivers. The fabricated antenna on a FR4 substrate shows an impedance bandwidth of 27.3% (1.5 GHz) at 5.5 GHz center frequency. The measured radiation patterns are similar to those of a conventional patch antenna with slightly higher gains of 6.4 dB and 5.2 dB at each resonant frequency

Package-level integrated antennas based on LTCC technology

We propose a novel package topology integrating multilayer miniaturized antennas. Such a functional package is suitable for the design of a system-on-chip device, or of system-on-package applications. A stacked patch antenna is designed and integrated in a package using a low temperature co-fired ceramic process. The overall size of the package is 10.3times10.3times1.3 mm3, and this package contains an 8.3times8.3times0.7 mm3 internal space for the integration of chip-scale packaged components. The package is mounted on a 20times20 mm2 ground plane to miniaturize the volume of the system. The antenna is designed to have two neighboring resonant frequencies at 5.264 and 5.355 GHz, resulting in a 140 MHz impedance bandwidth. However, the measured resonant frequencies occur at slightly higher frequencies due to manufacturing tolerances. Radiation patterns are similar to a conventional patch antenna. In addition, various parasitic effects rooted in the package size, ground size, antenna height, SMA connector, via misalignment, and the number of via holes and their locations are fully investigated

Bow-tie-shaped meander slot antenna for 5 GHz application

A bow-tie-shaped meander slot antenna fed by a microstrip line is proposed for 5 GHz applications. A conventional bow-tie slot antenna has a broad bandwidth; however, it is relatively large, and is thus inappropriate for miniaturized communication systems. Meanwhile, the meander slot antenna has small size, but its bandwidth is quite narrow. To realize miniaturized antennas having large bandwidth, we combine the bow-tie slot and meander slot geometries heuristically. Simulation results, confirmed by measured data, show that, for antennas designed to operate at 5.25 GHz, the proposed antenna is 65.5% smaller in size than the bow-tie antenna and the bandwidth is 3 times larger than that of the meander slot antenna.

Integration of Antenna and Feeding Network for Compact UWB Transceiver Package

This paper presents a low-temperature co-fired ceramic (LTCC) package incorporating an integrated ultra-wide-band (UWB) antenna, antenna-feeding network, and internal space for integration of a compact UWB transceiver chip. The area underneath a planar monopole antenna ground plane is utilized for integration of transceiver components. The LTCC package has overall dimensions of 20 × 20 × 1.2 mm3. The measured bandwidth of the integrated UWB antenna is 6.4 GHz starting from 4.75 to 11.15 GHz and the radiation patterns are suitable for indoor wireless communication environment. The fabricated package reveals reasonable time-domain characteristics. In addition, the practical application of the proposed package geometry is discussed.

Multi-Radiating-Element Printed Inverted-F Antenna With Independent Resonant Frequencies for Bandwidth Enhancement

This letter demonstrates a simple yet very effective method of bandwidth enhancement for popular printed inverted-F antennas (PIFAs). An additional radiating element is printed on the other side of the substrate, on the same side as the partially modified ground plane. Together with the primary radiating element, these provide different three electrical paths. The bandwidth of the antenna can be enhanced substantially by optimally locating the corresponding resonant frequencies. Most of all, each of the three radiators has negligible effect on the performance of the other two radiators, implying that they can be designed independently. While maintaining the far-field radiation patterns, as much as 12.6% increase in the relative bandwidth over the 7.0% bandwidth of a conventional PIFA is demonstrated.

Bandwidth property of folded planar inverted-F antennas

The bandwidth property of a folded planar inverted F antenna (PIFA) is investigated. In a folded PIFA, a part of the radiating element of the antenna is patterned on the backside of the substrate, resulting in both bandwidth enhancement and size reduction. Between the radiating elements on the top and bottom of the substrate, an electrical connection is maintained by two via holes. When these two via holes are positioned at different locations, a secondary electrical path is provided and a bandwidth enhancement is achieved. Experimental results show that the relative bandwidth of the proposed PIFA is more than 2% larger than that of a conventional PIFA on the same size substrate, while maintaining nearly the same radiation patterns. Both the simulated and experimental results for the proposed PIFA are provided along with a comparison with a conventional PIFA.

A Compact Broadband Capacitively-Loaded Antenna for UHF Application

In this work, a modified capacitively loaded antenna has been designed and fabricated. The desired capacitive impedances are achieved by fixing the space between the conductor rings with dielectric materials. Because the performance of the antenna is affected by the thickness of the dielectric rings, Chebyshev function is applied in this study. The antenna input impedance is mainly controlled by the length of the conical matching network, and the additional size reduction can be achieved by current distribution on the antenna. The lowest limit of the operating bandwidth is improved about 80 MHz in the lower frequency region, compared with the conventional antenna. The broadside radiation patterns of the proposed antenna are enhanced. Also, the size of the antenna is less than a third of the conventional antenna. The measured results show that the proposed capacitively loaded antenna can be applicable to wireless communication systems requiring the wideband operation.

Package-level integration of LTCC antenna

In this paper, a stacked patch antenna is designed and integrated in a package using a low temperature co-fired ceramic (LTCC) process for 5 GHz application. The total size of the package is 10.3 times 10.3 times 1.3 mm3 and this package contains 8.3 times 8.3 times 0.7 mm3 space for integration of chip scale packaged components. Numerical analysis exhibits that the designed antenna has two neighboring resonant frequencies of 5.264 GHz and 5.355 GHz with 140 MHz impedance bandwidth, while measured resonant frequencies occur slightly higher frequency region due to manufacturing tolerances

Design of Miniaturized Broadband Parasitic Patch Antenna Using Reduced Size Main Patch with U-Shaped Parasitic Patches

This paper proposes miniaturized broadband parasitic patch antenna. The proposed antenna consists of a probe fed reduced size main patch and U-shaped parasitic patches. The parasitic patches are incorporated to the radiating edges of the main patch to miniaturize the antenna size. The broadband impedance matching can be achieved by either E-plane or H-plane electromagnetic coupling between main patch and parasitic elements. The size of radiating elements is and the overall dimension of designed antenna with substrate and ground plane is . The fabricated antenna on a FR4 substrate shows two resonant frequencies(5.12 GHz and 6.08 GHz) with 27.3 %(1.5 GHz) fractional bandwidth at 5.5 GHz center frequency. The calculated and measured radiation patterns are almost similar to conventional patch antenna.

Wideband planar folded monopole antenna with tapered resistively loadings

A wideband planar folded monopole antenna with resistively loadings is proposed. This antenna is designed to cover the extremely wide frequency region, 30 MHz to 2000 MHz. By locating loadings at the upper part of the antenna, the loaded monopole antenna operates as a travelling-wave antenna. In addition, to reduce the total length of the monopole, upper part of the antenna is folded. A width of the line, a total length, a folded length, and the distance between the lines are optimized. Moreover, the wideband RF transformer is utilized. Due to the operating range of this transformer, VSWR of the fabricated antenna becomes worse than that of the simulation at the high frequency region. In case of the ideal impedance transformer, a measured VSWR of the proposed antenna agrees well with the simulated values. Therefore, additional research about a low-loss transformer operating in required bands should be performed to obtain the similar measured result close to the simulated one. From these results, the proposed antenna geometry can be applicable for the broadband wireless communication systems, especially in military vehicle antenna systems.