Telecoms, Datacoms, Wireless, IoT


The AATI SmartSwitch designed for the active antennae in GSM and GPS applications

5 November 2003 Telecoms, Datacoms, Wireless, IoT

An active antenna is an antenna with a built in LNA (low noise amplifier) used to amplify a very weak signal. A DC voltage, somewhere between 3 and 5 V, typically feed these antennas with a current consumption usually below 50 mA.

Active antennas will be used in satellite receivers, GSM phones, and mobile GPS units and in combination antennas applications, combining for example, both GPS and GSM functions in a common aerial.

Implementation for a satellite receiver
Implementation for a satellite receiver

For both satellite and GSM receivers AATI has been designed in with the SmartSwitch family from Advanced Analogic Technologies. The engineer requires a switch that powers the antenna while at the same time limiting the current in short circuit conditions. Active antennas are usually external devices making the system more vulnerable to damage in connectors, etc, and hence protection is needed. The AAT4610A and AAT4618 devices are examples of products suited to this application. The very low RDS (on) of the SmartSwitch ensures that full power is delivered to the antenna and not wasted in the switch, while the current limit protects both the antenna and the power supply from damage.

The AAT4610A has the advantage that the current limit can be programmed with an external resistor to very low values down to 130 mA. The AAT4618 provides a fault flag that indicates to the system if the antenna is short-circuited. Several other product options are also available.

As an alternative to a SmartSwitch one could use a low noise LDO, such as the AAT3215. With a built in current limit, the antennas will be protected from short-circuits and the enable pin could be used to control the power to the antenna.



Credit(s)



Share this article:
Share via emailShare via LinkedInPrint this page

Further reading:

Power amps for portable radio comms systems
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
CML Micro expands its SµRF product portfolio with a pair of high efficiency single- and two-stage power amplifiers that offer outstanding performance for a wide range of dual-cell lithium battery-powered wireless devices.

Read more...
RF agile transceiver
Altron Arrow Telecoms, Datacoms, Wireless, IoT
The AD9361 is a high performance, highly integrated RF Agile Transceiver designed for use in 3G and 4G base station applications.

Read more...
Choosing a GNSS receiver
RF Design Telecoms, Datacoms, Wireless, IoT
Applications requiring sub-ten-meter positioning accuracy today can choose between single-band or dual-band technology. While this decision might seem as simple as flipping a coin, it is far from that.

Read more...
Tri-Teq’s latest range of filters
RFiber Solutions Telecoms, Datacoms, Wireless, IoT
Tri-Teq recently presented its latest filter products, which included passive and co-site mitigation filters (lumped element and suspended substrate technologies) and tunable filters (bandpass and harmonic switched filters).

Read more...
Why GNSS positioning precision is enabling the next wave of IoT applications
iCorp Technologies Editor's Choice Telecoms, Datacoms, Wireless, IoT
While high-performance GNSS implementations are achievable with few limitations, most real-world applications must balance power consumption, form factor and accuracy requirements.

Read more...
The evolution of 4D imaging radar
Altron Arrow Telecoms, Datacoms, Wireless, IoT
4D imaging radar is redefining automotive sensing with unmatched precision, scalability and resilience and, as global adoption accelerates, this technology is poised to become a cornerstone of autonomous mobility.

Read more...
Links Field Networks: The perfect fit for telematics in Africa
Links Field Networks Telecoms, Datacoms, Wireless, IoT
Operating at the intersection of global SIM innovation and local market intelligence, Links Field Networks has emerged as a premier provider of telematics-oriented connectivity across Africa and beyond.

Read more...
RF direct conversion receiver
iCorp Technologies Telecoms, Datacoms, Wireless, IoT
The CMX994 series from CML Micro is a family of direct conversion receiver ICs with the ability to dynamically select power against performance modes.

Read more...
Bridging the future with RAKWireless WisNode devices
Otto Wireless Solutions Telecoms, Datacoms, Wireless, IoT
The WisNode Bridge series by RAKWireless is designed to convert traditional wired industrial protocols like RS485 and Modbus into LoRa-compatible signals.

Read more...
Mission-critical RF transceiver
Vepac Electronics Telecoms, Datacoms, Wireless, IoT
The Iris SQN9506 from Sequans Communications is a wide-band RF transceiver that operates from 220 MHz to 7,125 GHz.

Read more...









While every effort has been made to ensure the accuracy of the information contained herein, the publisher and its agents cannot be held responsible for any errors contained, or any loss incurred as a result. Articles published do not necessarily reflect the views of the publishers. The editor reserves the right to alter or cut copy. Articles submitted are deemed to have been cleared for publication. Advertisements and company contact details are published as provided by the advertiser. Technews Publishing (Pty) Ltd cannot be held responsible for the accuracy or veracity of supplied material.




© Technews Publishing (Pty) Ltd | All Rights Reserved