Wireless fidelity, or Wi-Fi, plays a major role in communications today. It enables devices to continuously connect to the 2.4 GHz and 5 GHz bands, for example, and also enables users with laptops and devices equipped with wireless network interfaces to connect to the Internet via broadband while roaming in the range of fixed access points (AP) or public hotspots.
Designed by Infineon the BFx840xESD product family is a series of discrete hetero-junction bipolar transistors (HBT) targeted at high-performance 5GHz band low noise amplifier (LNA) solutions in Wi-Fi applications. BFx840xESD transistors are produced with the 80-GHz fT silicon-germanium:carbide (SiGe:C) B9HFM process using special engineering geometry to reduce parasitic capacitance between the substrate and the transistor, which degrades high-frequency characteristics. As a result, with only 8 passive components and no input matching elements, the BFx840xESD series achieves 18dB gain and best-in-class 0.96dB noise figure in a 5GHz band application circuit.
The BFx840xESD RF transistor series allows engineers to increase the RF link budget and signal-to-noise ratio (SNR) of their AP routers and mobile stations to cover wider areas. This is particularly important when a higher order modulation scheme is used, for example in emerging very high throughput wireless specifications such as 256 quadrature amplitude modulation (QAM) in IEEE 802.11ac, which defines more stringent SNR requirements for both the AP and the client.
The first B9HFM SiGe:C transistors are available in the standard SOT-343 package (BFP840ESD), the flat-lead TSFP-4-1 package (BFP840FESD) and the low-height 0.3mm TSLP-3-9 package designed specifically for modules (BFR840L3RHESD).
Features
- High transition frequency fT = 80GHz
- Best-in-class RF performance
- High maximum RF input power
- 1.5kV HBM ESD robustness
- Inherently matched in the 5GHz band
- Achieves highest gain (18dB) and best-in-class noise figure (0.95dB) with only eight external passive components
- Low power consumption, ideal for mobile applications
- Low voltage supply capability e.g. VCC = 1.2V and 1.8V
- Available in standard, flat lead and ultra-low-height packages
Applications
- The BFx840xESD series is specifically designed to be used as a 5-6GHz low noise amplifier (LNA) for Wi-Fi 802.11 a/n/ac standards. The series is aimed at consumer products such as WiFi access point (AP) routers and Wi-Fi modules.
- Other possible applications include:
- Mobile and fixed connectivity applications: WiMAX and UWB
- Satellite communication systems, such as satellite radio (SDARs, DAB), navigation systems (e.g. GPS, GLONASS) and C-band LNB (1st and 2nd stage LNA)
- Ku-band LNB front-end (2nd stage or 3rd stage LNA and active mixer)
- Ka-band oscillators (DROs)
