A Single Chain 800M/1.8G/2.4GHz Multistandard Transceiver With Multibranch Transformer for Low-Cost IoT Applications

An 800M/1.8G/2.4GHz multi-band multi-standard single chain transceiver is presented to support terminals under NB-IoT, BLE and ZigBee protocols. The multi-branch co-wound transformer structure co-designed with RF front-end blocks (i.e., LNA & Power Mixer) is proposed and adopted for compact and efficient in-out matching with moderate Q value. Such co-designed topology enables the single transceiver chain to cover wide-spreading frequency ranging over three times of its minimum band frequency, without compromising performance. The measurement shows that, in receiver chain, the sensitivity is better than −102 dBm, consuming less than 20mW, in transmitter chain, the EVM is 4.63% and 5.2% for NB-IoT multi-tone 12-tone transmission with 0dBm output power in LB and MB. The transceiver has been implemented in 65nm CMOS process, with <inline-formula> <tex-math notation="LaTeX">$1.5mm^{2}$ </tex-math></inline-formula> and <inline-formula> <tex-math notation="LaTeX">$0.6mm^{2}$ </tex-math></inline-formula> for receiver and transmitter, respectively. The design is consistent with the requirement of low-cost multi-standard Internet-of-Things (IoT) applications.