Frequency Reconfigurable Multiband Handset Antenna Based on a Multichannel Transceiver

Abstract

Abstract-The upcoming standards of wireless communications result in additional and more stringent requirements for antennas in mobile phones. In this paper, we present a frequencyreconfigurable antenna that could potentially be suited for future mobile devices. Frequency reconfigurability is achieved through a cluster of mutually coupled antenna elements that are excited with frequency-dependent weights using a multichannel transceiver. We report a mobile handset antenna cluster measuring 15 x 15 x 1.6 mm 3 that covers the frequency bands of 1.7-2.7, 3.3-4.5, and 5.475-6.425 GHz with an antenna efficiency better than 90 %. The operation of the antenna cluster is experimentally verified by feeding all the antenna elements with proper weights using tailor-made power splitters that represent a multi-channel transceiver with adjustable amplitude and phase in each branch. The results obtained with the feed networks suggest the feasibility of the reconfigurability concept, and pave way for co-design of the antenna and the transceiver.

Combinatory Feeding Method for Mobile Applications

“…4 is due to coupling between the two antennas on the handset. As explained in [15], the coupling occurs due to short electrical distance between the antennas. Improving the efficiency would require the use of additional decoupling methods, such as neutralization lines [21] or defected ground structures [22], although the practicality of such methods in the proposed application is questionable.…”

“…Weighted feeding [14], [15] is a technique used to improving the matching efficiency of a multiport antenna. The method utilizes the coupling between antenna elements in a coupled antenna cluster to produce a single antenna with high efficiency.…”

“…Combinatory feeding is a novel method introduced in this letter. In contrast to the designs presented in [14] and [15], the method improves the best achievable matching of an antenna cluster by dynamically manipulating the number of antenna feeds. To explain the concept, we will first consider a simple example.…”

“…The method relies on special multichannel transceiver that is used to weight the feeds of a multielement antenna cluster. This letter significantly extends the method by introducing a completely new combinatory feeding scheme, which significantly improves the achievable efficiency without introducing any additional hardware compared to the designs in [15] and [16].…”

A New Design Method for Frequency- Reconfigurable Antennas Using Multiple Tuning Components

“…The antennas were not tuned in their aperture, wherefore only the total efficiency could be influenced while the radiation efficiency remained fixed. A somewhat similar concept was proposed in [48], where the transceiver was used to excite or receive the antenna elements with frequency-dependent weights. Again, since no tuning was performed in the antenna aperture, the radiation efficiency was not affected.…”