This paper presents a 900 MHz zero-IF RF transceiver for IEEE 802.15.4g Smart Utility Networks OFDM systems. The proposed RF transceiver comprises an RF front end, a Tx baseband analog circuit, an Rx baseband analog circuit, and a ΔΣ fractional-N frequency synthesizer. In the RF front end, re-use of a matching network reduces the chip size of the RF transceiver. Since a T/Rx switch is implemented only at the input of the low-noise amplifier, the driver amplifier can deliver its output power to an antenna without any signal loss; thus, leading to a low dc power consumption. The proposed current-driven passive mixer in Rx and voltage-mode passive mixer in Tx can mitigate the IQ crosstalk problem, while maintaining 50% duty-cycle in local oscillator clocks. The overall Rx-baseband circuits can provide a voltage gain of 70 dB with a 1 dB gain control step. The proposed RF transceiver is implemented in a 0.18 μm CMOS technology and consumes 37 mA in Tx mode and 38 mA in Rx mode from a 1.8 V supply voltage. The fabricated chip shows a Tx average power of −2 dBm, a sensitivity level of −103 dBm at 100 Kbps with , an Rx input P_1dB of −11 dBm, and an Rx input IP3 of −2.3 dBm.

IoT networks on large ships are known to face challenges, such as severe signal attenuation due to the complex steel bulkhead structure inside the ship. However, reliable connectivity is still required to monitor critical facilities such as engine rooms. This study presents an evaluation study of an IoT network using the IEEE 802.15.4 DSME MAC protocol for reliable data collection within a ship. We investigate the impact of ship-specific characteristics on signal propagation and analyze the feasibility of utilizing the DSME MAC protocol. We also compare the viability of 2.4 GHz and sub-1 GHz communication within a ship. In addition, we strategically select router locations and evaluate the stability and time sensitivity of the constructed network. The experimental results demonstrate the feasibility and reliability of the proposed multi-hop wireless network for seamless data transmission onboard ships.

In this paper, we have proposed VGA for MB-OFDM UWB application using CMOS 0.18 mum technique. The proposed VGA can vary from 31 - -30dB and 3 dB bandwidth is around 200 MHz. It has 3-stage cascade structure and DC offset cancellation. It consumes less than 4 mA for 1.8 V bias voltage.

This paper compares performance of three transmitter/receiver (T/RX) switch structures, which can be included as UWB RF transceiver. They are designed using complementary metal-oxide semiconductor (CMOS) 0.13 um technology and simulated each structure. They can be operated from 3 to 5 GHz and package model are applied for chip on board(COB) test. They have 1.8 dB insertion loss and more than 30 dB isolation at 5 GHz.