Circular active integrated antenna with push-pull oscillator

A new oscillating circular patch antenna with two bipolar transistors operating in push-pull mode is presented. By using a circular instead of a rectangular patch the stability of the operating frequency is increased and second-harmonic radiated power is decreased. High radiated power and very linear frequency tuning are observed. Radiation patterns show no degradation due to patch modifications.     

AC-coupled complementary push-pull ECL circuit with 34 fJ power-delay product

The authors describe the first experimental result of a high-speed low-power ECL-based AC-coupled complementary push-pull circuit. Implemented in a 0.8 mu m high-performance fully complementary bipolar technology with 50 GHz n-p-n transistors and 13 GHz p-n-p transistors, a power-delay product of 34 fJ (23.2 ps at 1.48 mW) has been achieved compared with 67 fJ (45 ps at 1.48 mW) for the n-p-n only ECL circuit.<>     

HBT大信号模型及PIN/HBT集成光接收前端设计

对GP大信号模型及其参数提取方法进行了研究,并对发射极尺寸为2μm×19μm的InP/InGaAs HBT进行了建模.模型的仿真结果表明,所建模型能较为精确地表征实际HBT器件的直流和高频小信号特性.基于建立的HBT大信号模型设计并制备出InP基PIN+HBT单片集成光接收前端,经在片测试,集成前端的3dB带宽可达3GHz.     

Analysis and design of wide-band SiGe HBT active mixers

The frequency response of SiGe HBT active mixers based on the Gilbert cell topology is analyzed theoretically. The time-varying operation of the active mixer is taken into account by applying conversion matrix analysis. The main bandwidth-limiting mechanisms experienced in SiGe HBT active mixers performing frequency conversion of wide-band signals is discussed. The analysis is verified by computer simulations using a realistic high-frequency large-signal SiGe HBT model. An active mixer design based on the Gilbert cell topology modified for wide-band operation using emitter degenerated transconductance stage and shunt feedback load stage is discussed. Experimental results are given for an active mixer implemented in a 0.8-/spl mu/m 35-GHz f/sub T/ SiGe HBT BiCMOS process.     

Design of microwave devices with adjoining positions of the source and loads

A new approach to formation of analysis and parametric-synthesis algorithms for microwave devices with adjoining positions of the source and one or several loads is proposed. The specific feature of this approach is the block notation of circuit transmission matrices formed in the course of decomposition of fragments and subsequent use of the corresponding block matrices in combination with impedance and/or admittance matrices of equivalent two-port or multiport circuits. The proposed algorithm is tested analytically with the use of the Richards theorem by considering two previously solved analysis problems. The results of solution of a synthesis problem for differential phase shifters are presented.     

Integrated active antenna with simultaneous transmit-receiveoperation

The authors present results for a novel two element active transmit-receive array using dual linear polarisation and sequential rotation. Each element includes an integrated oscillator and amplifier mounted on orthogonal edges of a square patch, such that transmit and receive paths are isolated and polarisation duplexed. The array gives in excess of 55 dB transmit-receive isolation at 3.77 GHz     

Integrated AlGaAs/GaAs HBT high slew-rate and wide band operationalamplifier

We report the design, fabrication, and test results of a wide band and high slew-rate voltage-mode operational amplifier using AlGaAs/GaAs HBT's. To select higher carbon doping concentration is more effective in reducing base resistance, and lower emitter doping concentration possess a smaller input capacitance to improve the device speed. The HBT operational amplifier has provided 500 V/μs high slew-rate, only 8 ns setting time and about 2 GHz unity-gain frequency. Common mode rejection ratio (CMRR) values of this operational amplifier are in the order of 70 dB with a small DC input voltage offset 5 mV, and the open-loop gain is about 40 dB     

RF and microwave phase shifter using complementary bias techniques

A novel method for the design of an RF phase shifter using a standard foundry process is described. This phase shift achieves very low and near-constant insertion loss. The proposed method uses `complementary' control techniques to keep variable parasitic resistance in a standard transistor to a minimum. Using an only single stage reflection configuration which employs N varactor diodes as a reflection terminator and M varactor diodes, a minimum insertion loss variation can be obtained. The technique is verified by measurement when N=M=1     

Linearised InGaP/GaAs HBT MMIC power amplifier with active biascircuit for W-CDMA application

A high linearity InGaP/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (MMIC) power amplifier is demonstrated using a new structure for a bias circuit for wideband-code division multiple access (W-CDMA) application. A one shunt capacitor is added to a novel active bias circuit and acts as a lineariser improving input P_{1 dB} of 16 dB and phase distortion of 5.1° for the hybrid phase shift keying (HPSK) modulated signal at the 28 dBm output power; the lineariser showing no significant increase of signal loss and chip area. The two-stage HBT MMIC amplifier exhibits a power-added efficiency (PAE) of 37%, a linear power gain of 24.5 dB, and an output power of 28 dBm with an adjacent channel power ratio (ACPR) of -45 dBc, under a 3 V operation voltage     

K-band HBT and HEMT monolithic active phase shifters using vector sum method

Two monolithic 3-bit active phase shifters using the vector sum method to K-band frequencies are reported in this paper. They are separately implemented using commercial 6-in GaAs HBT and high electron-mobility transistor (HEMT) monolithic-microwave integrated-circuit (MMIC) foundry processes. The MMIC HBT active phase shifter demonstrates an average gain of 8.87 dB and a maximum phase error of 11/spl deg/ at 18 GHz, while the HEMT phase shifter has 3.85-dB average measured gain with 11/spl deg/ maximum phase error at 20 GHz. The 20-GHz operation frequency of this HEMT MMIC is the highest among all the reported active phase shifters. The analysis for gain deviation and phase error of the active phase shifter using the vector sum method due to the individual variable gain amplifiers is also presented. The theoretical analysis can predict the measured minimum root-mean-square phase error 4.7/spl deg/ within 1/spl deg/ accuracy.     

Use of active loads with MSM photodetectors in digital GaAs MESFETphotoreceivers

Illuminated metal-semiconductor-metal (MSM) photodetectors display a current-voltage characteristic that saturates with increasing bias voltage and resembles the output characteristics of a field-effect transistor (FET). It is shown that operating an MSM photodetector with a GaAs FET active load can produce output voltage signal swings of over 80% of the power supply voltage from less than a 1 decade change in the MSM photocurrent, which may in turn be produced by only a 0.1 mW change in the input optical power. This swing allows the circuit to be used as an extremely compact optical input to high-speed digital gate circuits without the need for any intervening amplifiers. For fully monolithic prototype optical input circuits, less than -6 dBm of peak optical input power provided noise-free switching of a standard buffered FET logic (BFL) inverter from DC up to 25 MHz     

准平面型InAlAs/InGaAs异质结双极晶体管和单片集成激光器驱动电路

提出和制作了准平面型InAlAs/InGaAs异质结双极晶体管。该管主要采用硅离子注入法在半绝缘磷化铟衬底中形成隐埋型集电区以代替台面型集电区。晶体管的实测结果如下:h_(fe)=100,f_T=10GHz(V_(CE)=3V,I_c=10mA)。作为单片光电集成方面的实例,研制成功了由三个InGaAs/InAlAsHBT和一个电阻组成的激光器驱动电路,其电流调制速率高达4Gbit/s。     

Noise relations of inverse active networks and complementary networks

A direct relation is derived to calculate the noise of an inverse active network from the noise of its pair. A similar relation for complementary networks is also derived. Applications of these relations are given.     

Integrated modeling of microwave food processing and comparison with experimental measurements.

This paper presents an integrated electromagnetic and thermal model for the microwave processing offood packages. The model is developed by combining the edge finite element formulation of the 3-D vector electromagnetic field in the frequency domain and the node finite element solution of the thermal conduction equation. Both mutual and one-way coupling solution algorithms are discussed. Mutual coupling entails the iterative solution of the electromagnetic field and the thermal field, because the physical properties are temperature-dependent. The one-way coupling is applicable when the properties are temperature independent or this dependence is weak. Mesh sensitivity and shape regularity for the edge element based formulation for computational electromagnetics are discussed in light of available analytical solutions for a simple wave guide. The integrated model has been used to study the electromagnetic and thermal phenomena in a pilot scale microwave applicator with and without the food package immersed in water. The calculated results are compared with the experimentally measured data for the thermal fields generated by the microwave heating occurring in a whey protein gel package, and reasonably good agreement between the two is obtained.     

A 75 GHz regenerative dynamic frequency divider with active transformer using InGaAs/InP HBT technology

This letter presents a high speed 2:1 regenerative dynamic frequency divider with an active transformer fabricated in 0.7 μm InP DHBT technology with f_T of 165 GHz and f_max of 230 GHz. The circuit includes a two-stage active transformer, input buffer, divider core and output buffer. The core part of the frequency divider is composed of a double-balanced active mixer (widely known as the Gilbert cell) and a regenerative feedback loop. The active transformer with two stages can contribute to positive gain and greatly improve phase difference. Instead of the passive transformer, the active one occupies a much smaller chip area. The area of the chip is only 469×414 μm² and it entirely consumes a total DC power of only 94.6 mW from a single -4.8 V DC supply. The measured results present that the divider achieves an operating frequency bandwidth from 75 to 80 GHz, and performs a -23 dBm maximum output power at 37.5 GHz with a 0 dBm input signal of 75 GHz.     

High-speed monolithic p-i-n/HBT and HPT/HBT photoreceiversimplemented with simple phototransistor structure

Monolithic photoreceivers, using the base-collector junction of an InP/InGaAs phototransistor structure for a p-i-n photodetector, have been fabricated for the first time. Bandwidths as high as 3 GHz and bit rates as high as 5 Gb/s, with sensitivities of -22.5 dBm and -21.5 dBm for light focused on the p-i-n or on the first stage transistor of the preamplifier, respectively, have been achieved. These results represent the highest operating speed demonstrated for any phototransistor-based receiver     

Linearised HBT MMIC power amplifier with partially RF coupled active bias circuit for W-CDMA portable terminals applications

A highly linear MMIC power amplifier for wideband code-division multiple-access (W-CDMA) portable terminals has been devised and implemented with a new integrated on-chip lineariser. The proposed lineariser, consisting of an InGaP/GaAs heterojunction bipolar transistor (HBT) active bias circuit partially coupled to RF input power together with a feedback capacitor, effectively improves gain compression with little insertion power loss and no additional die area. The optimised lineariser improves maximum output power (P1 dB) by 2 dB and adjacent channel leakage power ratio (ACLR) by 4 dB, and the implemented HBT MMIC power amplifier exhibits a P1 dB of 30 dBm, a power gain of 30 dB, a power added efficiency of 42% at the maximum output power under an operation voltage of 3.4 V, and an ACLR of -34 dBc at 27 dBm of output power.     

A 3.2-V operation single-chip dual-band AlGaAs/GaAs HBT MMIC poweramplifier with active feedback circuit technique

This paper describes the design and experimental results for a 3.2-V operation single-chip AlGaAs/GaAs heterojunction bipolar transistor (HBT) monolithic microwave integrated circuit (IMMIC) power amplifier for GSM900 and DCS1800 dual-band applications. The following two new circuit techniques are proposed for implementing the power amplifier. One is an on-chip HBT bias switch which in turn switches the amplifier between 900 and 1800 MHz. The proposed switch configuration allows the switch using a high turn-on voltage of 1.3 V of AlGaAs/GaAs HBT's to operate with a 3-V low supply voltage, because the switch circuitry needs no stacked configuration. The other is an active feedback circuit (AFB) to prevent permanent failure of HBT's in the output power stage even under severe conditions of oversupply voltage and strongly mismatching load. Experimental results revealed that the proposed feedback circuit, which works as a voltage limiter, can protect the output stage HBT's from an excessive collector voltage swing even when the amplifier is operated under a condition of a 5-V oversupply voltage and a 10:1 voltage standing-wave ratio (VSWR) mismatching load. Under a normal condition of 3.2 V and a 50-Ω matching load, the IC is capable of delivering an output power of 34.5 dBm and a power-added efficiency (PaE) of 52% in a GSM900 mode, and a 32-dBm output power and a 32% PAE in a DCS1800 mode     

Vertical microstrip transition for multilayer microwave circuits with decoupled passive and active layers

A novel broadband (including dc) microstrip-to-microstrip vertical transition for multilayer microwave circuits is proposed. This transition solves the problem of the discontinuity typically appearing in via hole transitions between two microstrip transmission lines in different layers. An analogy existing between this transition and a rectangular coaxial line is discussed. A parametric study alongside with the experimental results of the transition are presented. Reduction of local oscillator to radio frequency leakage in a mixer with this transition is demonstrated.     

Low-power low-noise active mixers for 5.7 and 11.2 GHz usingcommercially available SiGe HBT MMIC technology

The authors demonstrate the application of a commercially available SiGe heterojunction bipolar transistor monolithic microwave integrated circuit technology to active mixers in future communication systems at 5.7 GHz and above. This technology can be used to realise circuits with less than 50 mW power consumption, conversion gains above 15 dB and small double sideband noise figures of 3.6 and 9.4 dB for 5.7 and 11.2 GHz Gilbert cell mixer circuits, respectively