High-efficiency InP-based DHBT active frequency multipliers for wireless communications

We present, for the first time, the performance of AlInAs/GaInAs/InP double heterostructure bipolar transistors (DHBT´s) as active frequency multipliers at frequencies of relevance to Wireless Communications applications. In particular, we present results comparing the performance of X6 (127→762 MHz) and X4 (762.5→3050.0 MHz) InP- and Si-based (NEC2107) multiplier circuits. A well-known multiplier circuit topology has been chosen as a vehicle, so that we can focus on active device comparison. The X6 InP-based multiplier exhibits output power and efficiency of +6 dBm and 11%, respectively, compared to +7.2 dBm and 4.8% of the Si-based circuit. The X4 InP-based multiplier exhibits output power and efficiency of +3.74 dBm and 8%, respectively, compared to -6.1 dBm and 0.4% of the Si-based circuit. The superior electronic properties of InP-DHBT´s enable high-conversion gain/highly DC-efficient multipliers, however, their nonexponential I_C-V _BE characteristic limits the maximum obtainable conversion gain at high-order frequency multiplication