2 Watt RF Power Amplifier: How to Read the Specs and Choose

When they got the 1 radio frequency amplifier marked 2W, many people's first reaction was to match it with watts. dBm is more commonly used in the RF field. The conversion formula is that the dBm value of power is equal to 10 times the logarithm of power wattage times 1000. According to this calculation, 1 W is 30 dBm and 2W is approximately equal to 33 dBm, that is to say, the nominal output power of a 2w rf power amplifier is approximately on the order of 33 dBm. However, unit conversion is only the first step. It will not tell you whether this device can be used or not. The caliber to be seen is still behind.

First distinguish the power caliber

Also written 2W, the actual meaning may be very poor. The output power must also state whether it is continuous wave or pulse, peak or average, at which frequency, in which compression state, and pulse width, duty cycle, power supply, temperature and load conditions. Several common power definitions in radio frequency cannot be mixed: P1dB is the output power when the linear gain of small signal is 1 dB lower than the extrapolated value, Psat is the output power close to the saturation region, P3dB is the output power when the gain is compressed by 3 dB, and the rated output power is the usage rating given by the manufacturer under the specified conditions. These four indicators describe different working conditions. If one is used to replace the other, the selection is easy to cause problems.

Gain, efficiency and linearity to look at together

power amplifier is not the greater the better. The small signal gain describes the amplification factor in the linear region, but once it enters the compression region, the gain will vary with the drive, so the large signal gain must be specified at which input or output power it is obtained. In terms of efficiency, drain efficiency is the ratio of RF output power to drain DC power, while power-added efficiency first deducts RF input power from the output and then compares it with DC power. The two cannot be mixed. Linearity can not only look at P1dB:OIP3 is the third-order intermodulation intercept point obtained by extrapolation of small signal dual-tone intermodulation, which is not the power that the device can continuously output; EVM reflects the error of modulation symbols relative to ideal constellation points, and ACLR reflects adjacent channel leakage. For linear modulation signals, it is not enough to judge that P1dB is qualified. For signals with high peak-to-average ratio, the power amplifier usually has to run back below the saturation power.

REVERSING REQUENT FOR APPLICATION AND FREQUENCY

The power level of 2 W should first fall to the specific application. Communication base station power amplifiers pay more attention to modulation linearity, average efficiency, bandwidth and adaptation of digital predistortion. Radar power amplifier pays more attention to pulse peak power, pulse width, duty cycle, phase stability and load mismatch. Scenarios such as industrial heating, plasma and medical RF sources often work in continuous wave conditions close to saturation, with emphasis on efficiency, reflected power protection and cooling under load changes. The frequency range should also be keyed: write a frequency band in the specification table, and confirm whether it guarantees gain, output power, matching or efficiency. The frequency band that can work does not mean that all indexes meet the standards.

The level of integration determines how much work you have to do

It is also a 2 W power amplifier, and the delivery form is very different. It can be 1 discrete transistors, which need you to complete biasing, input and output matching and heat dissipation. It can also be MMIC, which integrates active devices and matching networks on the same chip. It can also be a power amplifier module, which packages the transistor or MMIC together with matching, biasing and connectors. Generally speaking, in the range of 1 W to 200W, MMIC or small modules are enough for lower power, while discrete transistors, power trays or multi-channel synthesis are required for higher power. The specific boundary is determined by frequency, continuous wave or pulse, bandwidth and heat dissipation, rather than a fixed wattage.

How to confirm after getting the sample

Once a candidate is selected, testing is a step around. Small signal test looks at S parameters, gain, gain flatness, input and output return loss, reverse isolation and stability; power scan looks at output power, gain compression, P1dB, Psat, drain efficiency and PAE, and the test system must deduct input and output path loss. The modulation signal also measures EVM, ACLR and spectrum regeneration, while the pulse power amplifier records pulse width, duty cycle, pulse repetition frequency and pulse sag. There is an easy-to-step pit: the typical curve given by the manufacturer often describes a representative sample, which is not equal to the minimum or maximum guarantee value of each 1 device. The formal acceptance shall be subject to the guarantee value of the data manual or the written specifications of both parties.

After aligning the caliber, index, application and delivery form, it is clear whether the 1 2 W RF power amplifier is suitable for your link. The power number is only the entrance. What really determines whether it can be used is the 1 set of test conditions and application boundaries behind it.