Cellular modems are frequently embedded into laptops and other mobile devices, such as netbooks and tablets. Typically these modems are multi-band and multi-protocol (GSM, CDMA, HSPA+, LTE, etc.), meaning they’re compatible with 2G, 3G, and even 4G technologies, as well as Wi-Fi and Bluetooth.

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It is therefore increasingly difficult to come up with an antenna that has the bandwidth—not to mention the capability—for either diversity reception or multiple-input multiple-output (MIMO). Today, as LTE becomes nearly ubiquitous, MIMO is an essential feature. Antenna maker SkyCross has been working on this RF problem and has some novel solutions.

SkyCross invented the innovative Isolated Mode Antenna Technology (iMAT) that was introduced several years ago. An iMAT antenna is a wideband device with two feed points, which lets one antenna serve as two for MIMO. It makes MIMO a reality in handsets and other space-limited devices.

SkyCross T-Series antennas are designed to support 4G/3G/2G/Wi-Fi/Bluetooth tablet applications and come in single-band, multi-band, and MIMO iMAT configurations.
Select figure to enlarge.

Now, SkyCross has created a version of this design called the T-Series that is optimized for tablet computers. The T-Series has a form factor created to fit the demands of ultra-thin tablets. These antennas combine the flexibility of connectorized notebook antennas with the sophistication and compact size of smart-phone antennas (see the figure).

T-Series antennas are produced in single-band or multi-band forms over the frequency range from 700 MHz to 2.6 GHz. Standard models are available, but these antennas can be customized to fit any multi-protocol, multiband configuration.

The feed is unbalanced 50 Ω with coax. The gain is greater than 0 dBi with a voltage standing-wave ratio (VSWR) of less than 2.5:1 over the bands of operation. The polarization is linear, and the radiation pattern is omni-directional. For 4G versions requiring MIMO, the T-Series device can be configured with multi-feedpoint iMAT provisions.

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