dc.description.abstract | This study investigates the systematic method in designing a highly-integrated RF front-end system based on the integration of bandpass filter and amplifier. Firstly, the design of a bandpass power amplifier is presented. It is achieved by integrating a coupled-line bandpass filter with a power amplifier, and a diode is also embedded in the filter structure to realize the RF switch. Then the proposed bandpass power amplifier is integrated with a single-to-balanced bandpass low-noise amplifier to achieve a highly integrated RF frontend system including single-pole-double-throw T/R-switch, bandpass filters for Tx/Rx, power amplifier, low noise amplifier, and balun. The receiver is design for 1.93 GHz to 2.07 GHz operation. The measured small-signal gain is more than 11.5 dB, the input/output return loss is better than 10 dB, the noise figure less than 2.9 dB, and good balance performance with 0.7 dB maximum amplitude imbalance and 2.3 degree maximum phase imbalance is demonstrated. The transmitter is design for 2.2 GHz to 2.3 GHz operation. At the center frequency 2.25 GHz, the measured small-signal gain is 8.2 dB, the input/output return loss is 21 dB/15.2 dB, the measured output power and power-added-efficiency are 25.8 dBm and 38.1% respectively at the 1-dB gain compression point and the output 3-order intercept point is at 38.3 dBm. Since both the transmitter and receiver integrate bandpass filters, good selectivity and stop-band rejection are achieved. Furthermore, for the garmonic suppression of transmitter, a better than -49.4 dBc suppression from 2nd to 5th harmonic output at the 1-dB gain compression point is also demonstrated.
This study also proposes a simple design flow with design equations for the abovementioned highly-integrated RF front-end system. The performance is verified using printed-circuit-board and discrete component. Further size reduction can also be achieved by using the integrated-circuit technology. | en_US |