Design of a Low Voltage Highly Linear 2.4 GHz Up-Conversion Mixer in 0.18 μm CMOS Technology

This paper presents a low voltage highly linear up-conversion mixer for 2.4 GHz IEEE 802.11b WLAN transmitter applications based on a Chartered 0.18 μm CMOS technology. In the proposed mixer, the double balanced Gilbert cell topology was adopted and the dual resistive current-reuse and current-bleeding techniques in both the driver and switching stages with a capacitive cross-coupling technique were used. The up-conversion mixer can convert a 10 MHz intermediate frequency signal to a 2.4 GHz radio frequency signal, with a local oscillator power of 0 dBm at 2.39 GHz. A comparison with conventional CMOS mixer shows that this up-conversion mixer has advantages of low voltage, low power consumption and high performance. The post-layout simulation results demonstrate that at 2.4 GHz, the circuit provides 7.1 dB of conversion gain and the input-referred third-order intercept point of 11.3 dBm, while drawing only 5 mA for the mixer core under a supply voltage of 1.2 V. The chip area including testing pads is only 0.65 × 0.75 mm.     

Design of a 30.5 GHz Transition for Gyro-TWT

A 30.5 GHz circular transition used to transmit TE₀₁ mode is proposed because of no suitable one available. Calculations and simulations indicate that it can transmit TE₀₁ mode with transmission efficiency over 0.99 (within a bandwidth of 3 GHz). At the same time, the good performance of it has been demonstrated in experiment. Furthermore, the transition has only a length of 80 mm much shorter than linear or the other nonlinear ones. Such short length is very helpful for construction of a compact microwave device.     

Design of 95 GHz, 2 MW Gyrotron for Communication and Security Applications

The design and the numerical simulation of the 95 GHz, 2 MW gyrotron for various kinds of communication, sensing and security applications is presented. The gyrotron is designed for the TE_24,8 operating mode. Various in-house developed and commercially available computer codes are used for the design purpose. A 4.25 MW electron gun is designed for the 2 MW of output power. The mode selection, cold cavity and the beam–wave interaction analysis are discussed for the design of weakly tapered open resonator type of interaction cavity. The parametric analysis of the interaction cavity and the electron gun is also presented.     

Bias optimization of 2.4 GHz double gate MOSFET RF mixer

The optimum biasing points and structural design parameters for novel nano-scale double gate MOSFET (DG-MOSFET) radio frequency mixers are investigated at 2.4 GHz. Our objective is to analyze and identify the correlation of the conversion gain of the mixer circuit with the signal amplitude of the local oscillator (LO) as well as different device parameters, such as the gate length (L _gate ), doping concentration (N _A ) and body thickness (t _Si ), thus minimizing signal loss and power consumption and increasing stability. The most important figure of merit is found to be the LO DC bias that determines the level of non-linearity in the transconductance response. Furthermore, we observe that in properly designed DG-MOSFETs $(\hbox{L}_{gate} \ge 3t_{Si}),\; \hbox{L}_{gate}$ and N _A have limited impact on the conversion gain of the mixer, while t _Si has a more significant role to play. Although the mixing performance of DG-MOSFETs is ultimately limited by the short channel effects perpetrated by any given structural constraint, an optimum body thickness t _Si exists in each case to maximize the conversion gain. Thus, we illustrate how 2D and quantum-corrected simulations can identify the optimum body thickness and optimum bias conditions in such compact nano-scale mixers.     

Design of Beam Tunnel for 42 GHz, 200 kW Gyrotron

A beam tunnel for a 42 GHz, 200 kW gyrotron for an Indian TOKAMAK system has been designed. The initial design of the beam tunnel has been carried out on the basis of the required electron beam parameters at the interaction cavity and the electron beam simulation of the magnetron injection gun. The design optimization of the beam tunnel has been done with the help of 3-D simulation software CST-Microwave Studio. In the simulation, the absorption, the reflection and the transmission of RF power by the beam tunnel have been analyzed. Three different lossy ceramics, Al₂O₃–SiC, AlN–SiC and BeO–SiC have been investigated during the simulation. The simulation results obtained with CST-Microwave Studio have been validated with another 3-D simulation software HFSS. The Q value of the beam tunnel for different ceramic material has also been analyzed to investigate the parasitic mode excitation in the beam tunnel.     

Design and Preliminary Experiment of 35 GHz Pulsed Extended Interaction Oscillator with Folded Waveguide

In this paper a 35 GHz pulsed extended interaction oscillator (EIO) was studied, with high current density electron gun based cylindrical and parallel shaped diode. The folded waveguide was employed as the slow wave structure (SWS) of the EIO. The transferring waveguide, electron gun and the EIO tube were designed and the corresponding testes have been finished, including the transmission characteristic of the SWS, the emitting ability of the electron gun and the performance of the EIO tube. Preliminary experiment results show that the pulsed power and the exciting frequency are about 150 W and 35 GHz, respectively, under conditions of the B_z 0.4 T, the high voltage 17 kV and the high current density 26 A/cm².     

Design of integrated 1.6 GHz, 2 W tuned RF power amplifier

This paper describes the design of an integrated tuned power amplifier specified to operate at Inmarsat satellite uplink frequencies from 1626.5 to 1660.5 MHz. The basic topology of the amplifier lies on the parallel tuned inverse class E amplifier that is modified by placing the DC-blocking capacitor into a new position and by adjusting the size of the capacitor to improve stability below the desired band. Further, the new positioning reduces losses between drain and load. The high currents flowing in the circuit made it necessary to use wide inductor width and high-Q finger capacitors in the on-chip resonator. The amplifier was implemented as a Gallium Arsenide (GaAs) integrated circuit (IC) that delivered 2 W of output power while the drain efficiency was ca. 56%. Measurements included source and load pulls to further improve the performance of the amplifier and to investigate the stability at small input drive levels.     

Design of a full-band CMOS UWB receiver and fast-hopping carrier generator for 3.1–10.6 GHz

This paper presents an interference rejection full-band UWB receiver and fast hopping carrier generator for 3.1–10.6 GHz. This receiver enables 11 bands of operation by embedding a tunable notch filter to eliminate interferers in a 5 GHz wireless local area network. The carrier generator can cover 3.1–10.6 GHz within less than 9.5 ns. The receiver, based on the proposed multi-band OFDM standard, consists of a zero-IF receive chain and required system noise figure, the receiver linearity specifications of which are discussed in this paper. It consists of a single-ended low-noise amplifier (LNA), a down-conversion mixer, a low-pass filter (LPF), and a programmable gain amplifier with an IO buffer. The LNA employs a common-gate topology of the 1st stage with dual-resonant loads, a cascade amplifier of the 2nd stage for mid-band resonance, and a tunable notch filter. The down-conversion mixer adopts a single-balanced architecture with LO cancellation. The LPF is implemented based on an active RC topology, and implements a four-stage programmable gain amplifier. The receiver dissipates 49.3 mA from a 1.8 V power supply. The average voltage conversion gain of the receiver IC is 73.5 dB, and the system noise figure is 8.4 dB. Input P1dB increases from ?36.8 dBm at 4 GHz to ?30.5 dBm at 10.3 GHz. The attenuation is 8.5 dB, which is achieved in the interference rejection band at 5.2 GHz. It occupies an area of 0.98 × 3.3 mm² including the bond pads.     

Design, implementation and measurement of a 120 GHz 10 Gb/s phase-modulating transmitter in 65 nm LP CMOS

A novel mm-wave phase modulating transmit architecture, capable of achieving data rates as high as 10 Gb/s is presented at 120 GHz. The circuit operates at a frequency of 120 GHz. The modulator consists of a differential branchline coupler and a high speed 4-to-1 analog multiplexer with direct digital input. Both a QPSK as well as a 8QAM constellation are supported. To achieve high output power, a 9-stage power amplifier is designed and connected to the multiplexer output. The complete chip is integrated in a 65 nm low power CMOS technology. Capacitive neutralization is used to achieve high gain and good stability for the MOS devices. Also, various differential transmission line topologies are investigated to achieve high performance in terms of loss and area consumption.     

Indoor Radio Propagation and Interference in 2.4 GHz Wireless Sensor Networks: Measurements and Analysis

In wireless sensor networks (WSNs), the performance and lifetime are significantly affected by the indoor propagation and the interference from other technologies using the 2.4 GHz band. Next to an overview of the propagation and coexistence issues in the literature, we present a model for analysing these effects in WSNs. We also present our measurements results on the indoor propagation, the interference of the microwave oven (MWO) and their impact on the performance of the WSN. The propagation measurements reveal significant influence of the multipath: changing a node position with a few centimetres or changing the communication channel can lead up to 30 dB difference in the received power. The power leakage of MWO has been observed around $-$ 20 dBm at 1 m distances to the oven. This leads to extra retries of the 802.15.4 messages which matches our simulation results: the packet success ratio at first try decreases to 30–40 %, which increases the average active time of the sensor, closely located to the MWO. We observe that the ON–OFF pattern of the MWO could be exploited by WSNs to improve the performance.     

An Extended-AMATA Indoor Propagation Model for GSM 900/1800 MHz and Wi-Fi 2.4 GHz Frequencies

In a previous article, we reported on a novel indoor propagation model; we called the AMATA model, which we applied at 900 MHz and 2.4 GHz frequencies. The model could be applied at both GSM and wireless LAN frequencies. The developed formula merits, on its own, as a novel fourth power effective attenuation equation, which relies on the number of wall separations within the floor. This paper reports an extended-AMATA indoor propagation model that generally describes university and office type buildings. A sample of four different multi-floor building structures that have a stone block type outer wall was chosen. Those flat roofed, stone built, multi floor buildings are very common, not only in Palestine, but probably in vast areas in the Middle East region. The new model benefits over the previous one, applied at 900 MHz, in that it can be extended to cellular base-stations, transmitting at 1800 MHz frequency and outdoor Wi-Fi basestations, as opposed to indoor access points, transmitting at 2.4 GHz. The work is of paramount importance to cellular and Wi-Fi network operators, transmitting at 900/1800 MHz and 2.4 GHz frequency bands. Our new model can be applied with a high confidence level to buildings, similar to the sample of buildings, we measured.     

2.4GHz的处理器

<正> 据《Semiconductor FPD World》2002年 Vol.21,No.6上报道,英特尔公司发表了[pentium4处理器2.40GHz]。该处理器采用了0.13μm工艺技术和300mm 圆片。另外,作为批量生产水平,它集成了世界上最快、最小(60nm)的 CMOS 晶体管。价格:每订购1000个需74820日元,另外,该公司的目标是到2002年末,使3GHz 的 Pentium4处理器出厂。     

A novel high-isolation RF-SOI switch for 2.4 GHz multi-standard applications

Taking advantage of 1 KΩ·cm high-resistivity substrate and special device structure, a novel stack-by-two Single-pole-double-throw (SPDT) switch is fabricated in 0.18 μm partially depleted silicon-on-insulator technology for power handling capability and linearity improvement, targeting 2.4 GHz multi-standard transceiver application. The measured insertion loss is −1.1 dB at 2.4 GHz. With stacked switching device, the circuit exhibits a high measured input input-referred 1 dB power compression point (IP1 dB) of 21.5 dBm, which has more than 7 dB enhancement compared to previous work. The measured isolation is 43 dB. The switch has a overall occupied die area of 1200 × 560 μm².     

Design of high-linearity 75–90 GHz CMOS down-conversion mixer for automotive radar

This paper presents a 75–90 GHz down-conversion mixer applied in automotive radar, which is characterized with high linearity, low local oscillator (LO) drive as well as high conversion gain (CG) using TSMC 65-nm CMOS general-purpose technology. The good linearity and isolation of mixer are required for automotive radar to cover short-middle-far range detection. The mixer includes an enhanced double-balanced Gilbert-cell core with series peaking transmission line and source degeneration technique for improving linearity and CG, two on-chip baluns and intermediate frequency (IF) buffer for IF test. Besides, to make the design more accurate and efficient, the modeling and design of millimeter-wave (mm-wave) passive devices are introduced. The mixer consumes 12 mW under 1.5 V. The input 1 dB compression point (P_1dB) is 2.5 dBm as well as IIP3 of 13.2 dBm at 80 GHz. High performances are achieved with the CG of 5 dB at 76 GHz with LO power of 0 dBm for frequencies of 75–90 GHz which covers the application of automotive radar frequency band (76–81 GHz) and LO-RF isolation of 33–37 dB for frequencies of 60–90 GHz. The area of the mixer is 0.14 mm², with PADs included.     

Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4×4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than 1μs.     

Design and fabrication of sub-μs silicon-on-insulator thermo-optic 4×4 switch matrix

A rearrangeable nonblocking silicon-on-insulator-based thermo-optic 4×4 switch matrix with spot size converters (SSCs) and a new driving circuit are designed and fabricated. The introduction of a spot size converter (SSC) has decreased the insertion loss to less than 10dB and the new driving circuit has improved the response speed to less than 1μs.     

2.4GHz射频通信模块

日本夏普公司研制利用2．4G此频谱扩散方式的射频通信模块已上市。最大的数据传输速度为ZMb／s。该公司采用独特的多值调制方式。在2471－2497MHZ的26MHz频带中,以3．SMHz为单位,可分成7个信道。在无线LAN标准规格IEEESOZ．11中,只能使用1个信道。在使用几个信道时,要防止几台设备间混杂通信。在家庭电器引发干扰时,能够探出除汽车以外的信道。用于POS（PointtoSales）末端和家庭网络的设备等。该模块由集成基带处理电路和AD／DA转换器单片IC和RF模块构成。调制方式为QPSK。电源电压为3．3V。耗散功率,接收时为600mw…     

2.4GHz频段无线技术标准

为了满足人们对无线通信技术的需求,现对工作于2.4 GHz（ISM）频段常用的短距离无线通信中ZigBee、蓝牙（Bluetooth）、WiFi三者的技术优势、缺点及总的市场趋势做了详细分析,证明它们的关系是既互为补充又相互竞争的。