Multiple Antenna Systems With Inherently Decoupled Radiators

Novel Architecture for LTE World-Phones

“…The proposed architecture was first conceptualized in 2003 [22]. Initial investigations were published in [23] and [24]. The concept was demonstrated at the high bands (1.85 GHz -2.17 GHz) in [14].…”

Self‐matched high‐ Q reconfigurable antenna concept for mobile terminals

“…Such an approach is proposed to have separate transmitter (Tx) and receiver (Rx) path throughout the FE [8][9][10], thus requiring separate Tx and Rx antennas. Since these two antennas need to cover only the transmit and receive channels in a band, they can be quite narrow band.…”

“…In [8,13] it is proposed to improve the isolation by introducing a spatial filter, where the spatial filter is synthesised by equipping the Tx with at least one more antenna than the Rx, resulting in a balanced Tx antenna and unbalanced Rx antenna. Isolation study of wide-band, medium-band and narrow-band antennas is conducted in [9,14] to show the advantage of narrow-band antennas in terms of isolation. The challenges of frequency tunable high-Q antennas have been discussed in [15][16][17].…”

“…The work in [17] highlights the efficiency issue of a tunable high-Q antenna by comparing it with a low-Q antenna. The effect of user on tunable high-Q antennas is studied in [9,18] As addressed in [15][16][17], there are some conceivable drawbacks of frequency tunable high quality factor (Q) antennas, which among other things are because of relative high current density on the antenna structure and limited tuning/matching component Q. Hence, the active antennas can exhibit high RF power loss, poor linearity and high dc power consumption.…”

High-Q antennas with built-in coils: For mobile devices

“…This poses enormous challenges to the design of antennas in small form factors due to the trade-off between size, bandwidth and efficiency [2]. In order to address this, it is proposed to separate the Transmitting (Tx) and Receiving (Rx) antennas [3]. In such a system, the Tx and Rx antennas only need to cover the requisite Long Term Evolution (LTE) channel Bandwidth (BW), which varies between 1.4 MHz and 20 MHz [1].…”