dc.description.abstract | Several microwave and millimeter-wave broadband high-efficiency frequency multipliers are presented in this dissertation for high frequency local oscillation (LO) systems. Two broadband high-efficiency frequency multipliers are designed in heterojunction bipolar transistor and pseudomorphic high electron-mobility transistor (HBT-HEMT) process. First, an 8 to 30 GHz broadband high efficiency, high output power frequency doubler is presented. A common-gate (CG)/common-source (CS) field effect transistor pair is employed in the balanced doubler. The anti-phase property of CG/CS balanced topology can eliminate the need for the additional balun, thus achieving potentially small chip area and reducing design complexity. With an 8-dBm input power, this work features a conversion gain of better than -4 dB with a fundamental rejection of better than 13 dB over the operation bandwidth. The saturation output power (Psat) is higher than 10 dBm. This work presents excellent figure-of-merit (FOM) of 25.14 as compared to other previously reported broadband doublers. A Ka-band monolithic high efficiency frequency quadrupler using a GaAs HBT-HEMT technology is also presented. The frequency quadrupler is constructed cascading two frequency doublers. The frequency doubler employs a modified common-base (CB)/CS topology to enhance the second harmonic efficiently. The dc bias condition, harmonic output power, conversion gain, and efficiency for variable configurations are investigated. Two phase-shifter networks are used to reduce phase error and improve the fundamental suppression. Between 23 and 30 GHz, the proposed frequency quadrupler features a conversion gain of higher than -1 dB with an input power of 4 dBm. The maximum conversion gain is 2.7 dB at 28 GHz with an efficiency of up to 8% and a power-added efficiency (PAE) of 3.6%. The maximum output Psat is higher than 8.2 dBm. The overall chip size is 2x1 mm2.
A 10.2-12.6 GHz high conversion gain high harmonic suppression balanced frequency tripler is implemented in GaAs HBT-HEMT process. A pair of CB/common-emitter (CE) HBTs is used to generate in-phase and out-of-phase harmonics. Two band-pass filters (BPFs) are utilized at inter-stage to enhance the harmonic suppression. A CG/CS HEMTs active balun is employed to combine the third harmonic in-phase and provide conversion gain. Furthermore, a LC resonator designed at the third harmonic frequency is employed at the input to enhance the conversion gain. The proposed frequency tripler shows a conversion gain of 2.8 dB, a fractional bandwidth of 21.2%, and a fundamental suppression of higher than 47 dB.
Two Gm-boosted frequency doublers are presented in chapter 4. First, a V-band 90-nm CMOS frequency doubler using active CS-based Gm-boosted technique is introduced. When the Gm-boosted technique is applied to the frequency multiplier designs, the input driving power reduces due to the boosted input voltage swing. Therefore, the conversion gain can be improved. The proposed frequency doubler exhibits a conversion of -3.3 dB and a fractional bandwidth of 26.5%. At 60-GHz output frequency, the maximum output Psat is higher than 0.8 dBm. A K-band doubly Gm-boosted differential CB frequency doubler using 0.18-um SiGe BiCMOS technology is also presented in this chapter. The doubly Gm-boosted configuration consists of an active CG topology and a passive capacitive cross coupling. The active CG Gm-boosted stage provides gain boosting mainly and the cross-coupled capacitor further boosts the gain of the CG Gm-boosted stage without additional dc power. The design methodology of the frequency doubler using Gm-boosted technique is presented. The comparisons of the current consumption and bandwidth using a CS Gm-boosted stage and a CG Gm-boosted stage with a cross-coupled capacitor are also addressed. Based on the doubly Gm-boosted configuration, the proposed frequency doubler achieves a conversion gain of -1.3 dB and a fractional bandwidth of 30.9%. At 26-GHz output frequency, the maximum output Psat is higher than 4.5 dBm. | en_US |