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Antennas are a big issue in any wireless system using multiple-input multiple-output (MIMO) technology. MIMO is already a big hit in Wi-Fi, WiMAX, and HSPA 3G. We soon will be seeing Long-Term Evolution (LTE) cell phones and other 4G cellular technologies that need a MIMO antenna solution. With that in mind, Mobile Mark designed its EDN268-400 Mobile Antenna to meet the needs of some MIMO applications.

Also known as spatial multiplexing, MIMO systems transmit different data streams on different transmitters with separate antenna elements. The data is received on multiple antennas and receivers, and then it is decoded and combined for recovery. The net result is greater data throughput and improved bandwidth efficiency. MIMO also provides a greater level of consistent and reliable coverage. The most common setups, 2x2 and 3x3 MIMO, require either two or three antennas at the transmitter and the receiver.

The Mobile Mark EDN268-400 comprises three antennas with coax feeds and dual-band (2.4 to 2.5 GHz and 4.9 to 6.0 GHz) coverage. This low-profile, surface-mount antenna is housed in a rugged, ultraviolet-resistant, ASA radome that measures 1.5 in. (38 mm) tall by 3.5 in. (89 mm) in diameter. Its standard configuration is low-loss RF-195 cable with surface-mount assembly plugs.

The EDN268-400 packages three separate antenna elements within a compact rugged radome (see the figure). There are three cable feeds, each with identical frequency coverage. A different cable feeds each antenna element. Each cable covers the entire 2.4- to 2.5-GHz and 4.9- to 6.0-GHz spectrum. Each antenna element provides 4-dBi gain with a voltage standing-wave ratio (VSWR) of less than 2:1. Other specifications include vertical polarization, 20-W maximum power, and an isolation between antennas of greater than 20 dB.

The MIMO Mobile Antenna will stand up to harsh environments. It has a water ingress rating of IPX7. Also, it has been tested to and has passed the EN61373:1999, IEEE1478-2001, and MIL-STD-810G industry and military shock and vibration standards.

Mobile Mark