hf/rf ZONE Products for the week of August 25, 2003
Agilent Technologies Says . . .
ATF-501P8: High Linearity E-pHEMT FET For Wireless
Through 6 GHz
New Transistor Enables Higher Channel Capacity, Ensures Higher
Reliability, Miniature LPCC Package Saves Valuable Board Space
Agilent Technologies Inc. introduced its highest linearity E-pHEMT (enhancement-mode pseudomorphic high-electron-mobility transistor) field effect transistor (FET) in a new lower thermal resistance version of the miniature 2 mm x 2 mm 8-pin leadless plastic chip carrier (LPCC) package.
The Agilent ATF-501P8 single-voltage E-pHEMT is optimized for use in transmitter power amplifiers and receiver low-noise amplifiers used in cellular/PCS/WCDMA base stations, low-earth-orbit satellite systems, terrestrial multichannel multipoint distribution systems (MMDSs), wireless local area networks (WLANs), wireless local loop (WLL), fixed wireless access, and other services operating in the 50 MHz to 6 GHz frequency range.
At 2 GHz, the single voltage operation Agilent ATF-501P8 provides +45.5 dBm third-order output intercept point (OIP3), resulting in a more efficient multi-channel amplifier capable of handling a greater number of voice and data channels. Its low thermal resistance of only 23°C/W (compared to 33°C/W for similar devices in the conventional LPCC package) enables the Agilent ATF-501P8 to dissipate nearly 2 W at +85°C ambient temperature while maintaining a chip temperature that assures high reliability. The ATF-501P8 also features +29 dBm linear output power (P1dB), 15 dB gain and 65 percent power-added efficiency at 2 GHz, combined with a low 1.0 dB noise figure. Its compact size of 2 mm x 2 mm saves valuable printed circuit board space.
Agilent remains the industry's only supplier of E-pHEMT devices that
feature single-voltage operation. With single-voltage operation, high-power
efficiency and superior RF performance, Agilent's E-pHEMT devices are the
logical choice to replace both single-voltage HBTs, with their higher noise
figures, and dual-voltage conventional PHEMT and GaAs HFET (heterostructure
FET) devices.
analogZONE Says . . .
When you pick up an Agilent RF data sheet you know right away that designing the product into a circuit is going to be a cinch because of the wealth of scattering data that is provided: That's for those of us who believe that RF is not black magic.
Agilent's designers have done a great job with this product. Its linearity is very good, it is a capable amplifier over a large spectrum with a decent medium power output, and it has a noise figure that puts most other products to shame.
As Agilent says, it is the only manufacturer of e-PHEMT product that requires only a single rail for operation, a major benefit; the data sheet focuses on 900 MHz and 2 GHz as the major operating spectrums -- which will be the case -- with a typical operational gate voltage of 0.55 with a Vds of 4.5 V and Ids set at 280 mA. Typical Gm is 1872 mmho with a gain leakage current of -0.8 µA; Typical gains are 15 dB at 2 GHz and 16.6 dB at 900 MHz, while the P1dBs are 29 dBm and 27.3 dBm. The PAE at 2 GHz is given as 65% and that at 900 MHz is 49%. The former is rather a suspicious number and I believe (from the characteristics given) that it is a typo for 55%. The ACLR (based on 3GPP TS 25.141 V5.3.1) at 2.14 GHz with an input power of -5 dBm is a typical 63.9 dBc with a 5-MHz offset bandwidth, and 64.1 dBc when that is increased to 10 MHz. The noise figure, of course, is the gem of the specifications, with a 1-dB typical at 2 GHz, making it a must-look-at product for LNAs across the complete spectrum of 50 MHz to 6 GHz
The ATF-501P8 is going to be very favorably looked at by designers of both the power end and the receive end of cellular/PCS, WCDMA, WLAN, MMDS and loops.
The ATF-501P8 is in production in a thermally-enhanced (pad is at RF ground) 2 mm x 2 mm LPCC-8 and is priced at $3.13 in 5 k lots.