Addressing carrier aggregation with narrow-band tunable antennas

Abstract

Abstract-Enhancing the operating bandwidth of antennas is particularly challenging when the antenna is confined in a very restricted volume, as is the case for mobile phones. However, increasing the bandwidth provides higher data rates to the users. Consequently, the carrier aggregation technology has been standardized. This paper proposes an antenna design that can address the bandwidth issue of new radio frequency standards, while coping with carrier aggregation requirements. Specifically, the paper presents a dual-antenna system, where each antenna exhibits a dualresonance. The low-bands of the radio frequency spectrum can be efficiently covered.

Efficiency‐based approach to quantifying ‘tuneability’ performance in frequency‐agile narrowband antennas

“…Thus, they also need efficient tuning to achieve a very wide operating bandwidths. Recent examples of the aperture tuning approach include the use of RF switches [3,7], varactor diode [4, 5, 8-12, 19, 21], RF MEMS [17] and CMOS [6] tuneable capacitors, PIN diodes [16], tuneable magneto-dielectric [33] and tuneable dielectric substrates (including liquid crystal substrates [18]) as well as liquid metal [13] tuning techniques. Each of these techniques permits the antenna to serve different bands at different times.…”

“…A key metric of interest for such antennas is 'tuneability' or frequency agility, recording the range of frequencies that can be addressed by the tuneable antenna. A survey of the contemporary literature suggests that this assessment is almost always supported by a stated range of measured tuneable input responses S 11 [4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21]. However, this makes no assessment of the radiation efficiency offered over the tuned range, reporting of which over a tuneable range was found to be much less widespread.…”

“…However, this makes no assessment of the radiation efficiency offered over the tuned range, reporting of which over a tuneable range was found to be much less widespread. The survey found that in nearly half of cases no efficiency data were given [7,8,10,13,15,16,[18][19][20], while in others values were given but the method used to measure them was not declared [6,9,17]. Of the papers found to have reported both efficiency values and the method by which these values were obtained (only 40% of those surveyed), none were found to have attempted to distil an efficiency-based approach to recording metrics of frequency agility.…”

On the Operating Principle of an LTE Handset Antenna with Multiple Closely-Located Radiators

“…One solution to the MIMO-related challenges is to use tunable antennas covering only part of the required frequency bands at a time [1]. Such antennas can be more robust to the effects of mutual coupling, but the required tunable circuit components (typically capacitors) are problematic from the point of view of Carrier Aggregation (CA).…”

Carrier Aggregation Compatible Mimo Antenna for Lte Handset

“…One solution to this issue is to use smaller antennas with tunable matching circuits [4][5][6]. With frequency tuning, antenna size can be reduced as the entire frequency band of a given radio system is not covered instantaneously.…”