Reconfigurable Multiband Antenna Booster Architecture for Different Environments

A passive matching network cannot match a device for more than one specific scenario. For this reason, a new approach capable of matching a 50 mm $\times50$ mm Internet of Things (IoT) device at 698&#x2013;960 MHz and 1710&#x2013;2170 MHz, using a single SP4T (Single Pole 4 Throw) switch to provide good impedance matching ( \vert \text{S}_{11}\vert < &#x2013;6 dB), across five different environment cases (free space, metal, bricks, wood, and human body), is presented. To validate the capabilities of the proposed reconfigurable matching network to match the surrounding environments, two extreme scenarios have been considered: 1) at free space and 2) when the prototype is placed at three different $h$ distances of 7, 15, and 20 mm ( $0.016 \lambda$ , $0.035 \lambda$ , and $0.046 \lambda$ , respectively, at the lower frequency of operation of 698 MHz) from four different materials: metal, bricks, wood, and human body. The proposed method can compensate for the effects of the close environment variations by commuting between matched states of the reconfigurable matching network. To validate it, a prototype is implemented and tested in all the enumerated materials. By using the proposed reconfigurable architecture, total efficiency is maximized in all cases. The total efficiency increased by 0.8 dB for the on-wood case, by 1.7 dB for the on-body case, by 1.9 dB for the on-brick case, and by 3 dB for the on-metal case compared to a solution where the same matching network is used for all cases

Mitigation of the finger loading effect in handset antennas

The effect of the human body over the radiation of handset antennas is a critical issue that have to be considered to ensure a good handset antenna performance. Among the human body effect, the finger is of particular interest since it is usually placed over the antenna area which may cause detuning and/or reduction of the efficiency. To mitigate the finger loading effects, a novel handset antenna consisting of two small antennas distributed along the ground plane is proposed. The distributed antenna system is compared with a single antenna having a broadband matching network, so both designs feature enough bandwidth to cover the GSM850 (824-890MHz) and GSM900 (880-960MHz) communication systems. The finger effect is analyzed in terms of efficiency using a phantom hand. Efficiency is measured for different finger locations concluding that the distributed antenna system is more robust to the finger loading effect.Peer ReviewedPostprint (published version

Mitigation of the finger loading effect in handset antennas

The effect of the human body over the radiation of handset antennas is a critical issue that have to be considered to ensure a good handset antenna performance. Among the human body effect, the finger is of particular interest since it is usually placed over the antenna area which may cause detuning and/or reduction of the efficiency. To mitigate the finger loading effects, a novel handset antenna consisting of two small antennas distributed along the ground plane is proposed. The distributed antenna system is compared with a single antenna having a broadband matching network, so both designs feature enough bandwidth to cover the GSM850 (824-890MHz) and GSM900 (880-960MHz) communication systems. The finger effect is analyzed in terms of efficiency using a phantom hand. Efficiency is measured for different finger locations concluding that the distributed antenna system is more robust to the finger loading effect.Peer Reviewe

Mitigation of the finger loading effect in handset antennas

The effect of the human body over the radiation of handset antennas is a critical issue that have to be considered to ensure a good handset antenna performance. Among the human body effect, the finger is of particular interest since it is usually placed over the antenna area which may cause detuning and/or reduction of the efficiency. To mitigate the finger loading effects, a novel handset antenna consisting of two small antennas distributed along the ground plane is proposed. The distributed antenna system is compared with a single antenna having a broadband matching network, so both designs feature enough bandwidth to cover the GSM850 (824-890MHz) and GSM900 (880-960MHz) communication systems. The finger effect is analyzed in terms of efficiency using a phantom hand. Efficiency is measured for different finger locations concluding that the distributed antenna system is more robust to the finger loading effect.Peer Reviewe

CPW balun for printed balanced antennas

In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation.Peer ReviewedPostprint (published version

CPW balun for printed balanced antennas

In coplanar waveguide (CPW) circuits, printed balanced antennas must be excited through baluns. These baluns often feature coplanar-to-slotline transitions that must be tuned and matched by electromagnetic optimisation, and may interfere with the antenna backward radiation. A new CPW balun for printed balanced antennas is presented and modelled. As its multimodal circuit model makes clear, it integrates an impedance-matching network within its structure that can be analytically designed. The balun has been experimentally tested, exhibiting good agreement with its circuit model and a weak electromagnetic interaction with the antenna radiation.Peer Reviewe