Aimed at CDMA and TDMA applications in the 1.8 to 2.0GHz band, Ericsson Components has launched its flagship RF power transistor amplifier. For this frequency range, the PTF10120 is rated at a groundbreaking 120W minimum output power - the highest available in todayýs marketplace.

Currently double the power of that offered by Ericssonýs nearest competitor, the enhancement-mode 2GHz device employs LDMOS (Laterally Diffused Metal Oxide Semiconductor) technology and gold metallization. As a result the PTF10120 exhibits a linear response of just ý0.5dB over the 1.8 to 2.0GHz range.

Prior to the PTF10120, several parallel devices would have been employed to develop the power needed for long range base station transmitters. Using new technology, Ericssonýs top of the range PTF10120 offers RF designers maximum signal power at lower costs and with a lower component count, reliability is increased too.

Designed to operate from a standard 28V supply, the part has a useful minimum power gain of 11dB at 1.95GHz, while at 100W the class AB two-tone third order IMD figure for the device is an impressive -32dB. Efficiency for the device is 40% at 120W output power, and with a drain-source breakdown voltage of 65V, the PTF10120 is rugged and robust.

Ion implantation and nitride surface passivation are used to ensure excellent device lifetime and reliability. To help in quality assurance programmes, 100% lot traceability is standard.

If one manufacturer announces a product and another manufacturer is working on something similar, or better, you can be sure that there will be a press release rather quickly to try and stop design wins for the first-announced part. I am impressed that Ericsson reacted in less than a week to an LDMOS product family that was on these pages last week. It takes my breath away a little because I wrote at the time that "these power levels are close to maxing out for the technology -- maybe another 3 dB more." And here we are a week later with the 3 dB! I'm not sure why, however, every manufacturer seems to be gushing about their products being great over the whole 1.8 to 2.0 GHz band: It is, after all, only about a 10% span.

Apart from the power levels from this device, which again validates Motorola's initial design of the LDMOS process, the power gain is about 1 dB higher than other claims and the efficiency is about what you would expect. The third order IMD is extremely impressive although I have problems about why the company would quote a number at the 100-W level, instead of 120 W. Nevertheless, this kind of specification number will make it much easier for base station designers to use a single DAC in their offerings for the transmit side. Ericsson is, of course, right in there in the mainstream of cellular business and the company certainly knows and understands what it needs to offer in its core products. This will be a extremely profitable product for the company.