Radiofrekvencijska pojačala snage u tehnologiji bipolarnoga tranzistora s horizontalnim tokom struje

The large-signal performance of the horizontal current bipolar transistor (HCBT) is investigated by extensive measurements and simulations, and its suitability for the radiofrequency power amplifier design is demonstrated by designing advanced high-efficiency and wideband power amplifiers. An accurate and calibrated scalar load-pull setup is firstly employed for the determination of the optimal input and output matching impedances for different HCBT structures to achieve the maximum output power. The HCBT in Class-AB regime at the fundamental frequency of 2.4 GHz provides up to 25 dBm output power with the gain of 11 dB, exhibiting optimal matching impedances close to 50 Ω. The suitability of different collector region designs is investigated by performing load-pull measurements for the HCBTs with uniform, n-well, and low-doped collectors, where the low-doped HCBT achieves the highest gain, whereas the n-well HCBT provides the highest collector efficiency in the power back-off power range. Due to its robustness in large-signal operation, the HCBT is analyzed in the regime where the load line penetrates the impact ionization region, for the base-emitter bias applied by either a voltage or current source. Additionally, the boundary of linear operation is found for the HCBT by developing a dedicated vector load-pull setup with the possibility of a time-domain waveform measurement in large-signal operation. A high-efficiency Doherty power amplifier is designed using discrete HCBTs at 2.4 GHz, where the amplifier achieves 38.7% collector efficiency with the modulated excitation of 3.5-dB peak to average power ratio. Finally, a wideband balanced amplifier with 700-MHz bandwidth at 2.4 GHz is designed, exhibiting efficiency greater than 35.6% over the bandwidth. The amplifiers provide a performance surpassing that of the most advanced power amplifiers implemented in costlier semiconductor technologies.Karakteristike bipolarnoga tranzistora s horizontalnim tokom struje (HCBT) analizirane su u režimu velikog signala pomoću detaljnih mjerenja i simulacija. Projektiranjem radiofrekvencijskih pojačala snage visoke korisnosti i frekvencijskog opsega, pokazana je pogodnost tehnologije za projektiranje modernih pojačala snage. Koristeći skalarni sustav za karakterizaciju u režimu velikog signala, određene su optimalne impedancije za maksimalnu izlaznu snagu za različite HCBT strukture. Na 2.4 GHz, HCBT dostiže izlaznu snagu od 25 dBm i pojačanje od 11 dB, a optimalne impedancije bliske su 50 Ω. Utjecaj kolektorskog doping profila na karakteristike tranzistora u režimu velikog signala analiziran je koristeći HCBT sa uniformnim, n-well, i niskodopiranim kolektorom, gdje HCBT sa niskodopiranim kolektorom postiže najveće pojačanje, a struktura sa n-well kolektorom, najvišu korisnost. Mjerenjima je određena granica linearnog rada za HCBT u režimu velikog signala, koristeći napredni vektorski mjerni sustav sa mogućnosti mjerenja vremenskih valnih oblika na visokim frekvencijama. Koristeći diskretni HCBT, projektirano je Doherty pojačalo visoke korisnosti koje postiže kolektorsku korisnost od 38.7% uz pobudu moduliranim signalom omjera vršne i srednje snage od 3.5 dB. Također, projektirano je pojačalo snage širine pojasa od 700 MHz na središnjoj frekvenciji 2.4 GHz, koje postiže korisnost od najmanje 35.6% unutar pojasa. HCBT pojačala snage postižu performanse usporedive ili veće od pojačala implementiranih u naprednim i skupljim poluvodičkim tehnologijama