摘要

This paper presents an ultrawideband low-noise amplifier chip using TSMC 0.18ˋ米m CMOS technology. We propose a UWB low noise amplifier (LNA) for low-voltage and low-power application. The present UWB LNA leads to a better performance in terms of isolation, chip size, and power consumption for low supply voltage. This UWB LNA is designed based on a current-reused topology, and a simplified RLC circuit is used to achieve the input broadband matching. Output impedance introduces the LC matching method to reduce power consumption. The measured results of the proposed LNA show an average power gain (S21) of 9ˋdB with the 3ˋdB band from 3 to 5.6ˋGHz. The input reflection coefficient (S11) less than ˋ9ˋdB is from 3 to 11ˋGHz. The output reflection coefficient (S22) less than ˋ8ˋdB is from 3 to 7.5ˋGHz. The noise figure 4.6每5.3ˋdB is from 3 to 5.6ˋGHz. Input third-order-intercept point (IIP3) of 2ˋdBm is at 5.3ˋGHz. The dc power consumption of this LNA is 9ˋmW under the supply of a 1ˋV supply voltage. The chip size of the CMOS UWB LNA is ˋmm2 in total. 1. Introduction The ultrawideband (UWB) system has become one of the major technologies for wireless communication systems and local area networks. The IEEE 802.15.3a ultrawideband (UWB) system uses a specific frequency band (3.1ˋGHz~10.6ˋGHz) to access data and employs the system of orthogonal frequency-division multiplexing (OFDM) modulation [1每3]. The frequency band consists of four groups: A, B, C, and D, with thirteen channels. Each channel bandwidth is 528ˋMHz, as shown in Figure 1. The system operates across a wide range of frequency 3.1每5ˋGHz or 3.1每10.6ˋGHz. The low frequency band from 3.1 to 5ˋGHz has been allocated for developing the first generation of UWB systems [4]. The system has several advantages such as low complexity, low cost, and a high data rate for the wireless system. In the front-end system design, a low-noise amplifier (LNA) is the first block in the receiver path of a communication system. The chief objective of the LNA is to reach the low-noise figure to improve the overall system noise [5]. The LNA must minimize the noise figure over the entire bandwidth, feature flat gain, good linearity, wideband input-output matching, and low power consumption. In the radio frequency circuit design, GaAs and bipolar transistors have performed fairly well. Nevertheless, these processes lead to increased cost and greater complexity. The RF front-end circuits using CMOS technology can provide a single-chip solution, which greatly reduces the cost [6]. With the rapid improvement of CMOS technology, it

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