The BA-DPA has been designed by using push-pull transistor
(CGH40090PP) that includes 2 pieces 45 W transistor in a single package.
Each signal is then divided by the branch-line coupler into two parts of nearly the same amplitude and with a 90[degrees] phase difference to drive each side of the push-pull transistor
amplifier, thus implementing the balanced design.
The study has been carried out on a 180 W high power push-pull transistor
. The focus of this investigation is not only on IM3 components but also fifth- and seventh-order components, as they become a non-negligible source of distortion for wide instantaneous bandwidth signals.
For applications requiring higher peak and average power, the MRF21180 is an internal impedance-matched push-pull transistor
that provides 160 XV peak power and 24 W average power while meeting the wideband CDMA mask.
Another amplifier was built using a Motorola model MRF21120 120 W/2.1 GHz/26 V push-pull transistor
. Table 2 lists the measured impedances for 120 W/12.1 dB gain at 1 dB compression.
Besides converting RF from unbalanced to balanced to drive the push-pull transistor
, these baluns also provide impedance transformation from 50 to 12.5 ohms.