60-GHz-band coplanar MMIC active filters

This paper presents the design and performance of 60-GHz-band coplanar monolithic microwave integrated circuit (MMIC) active filters. To compensate for the loss of the passive filter, a resonator composed of a quarter-wavelength line is terminated by a circuit with a constant negative resistance over a wide frequency band. Cross-coupling is introduced to make the attenuation poles on both sides of the passband. We develop two types of two-stage filter: one with medium bandwidth and the other with narrow bandwidth. The former shows an insertion loss of 3.0 dB with a 3-dB bandwidth of 2.6 GHz and a rejection of larger than 20 dB at a 3-GHz separation from a center frequency of 65.0 GHz. This filter also shows a noise figure of 10.5 dB. The latter filter shows an insertion loss of 2.8 dB with a 10-dB bandwidth of 2.1 GHz at a center frequency of 65.0 GHz. It also shows an output power of 5.0 dBm at a 1-dB compression point. The loss variation due to temperature variation is successfully compensated using a gate bias control circuit. The size of the MMIC filters is 2.5 mm/spl times/1.1 mm.     

An electronically tunable microstrip bandpass filter using thin-film Barium-Strontium-Titanate (BST) varactors

A tunable third-order combline bandpass filter using thin-film barium-strontium-titanate varactors and fabricated on a sapphire substrate is reported. Application of 0-200-V bias varied the center frequency of the filter from 2.44 to 2.88 GHz (16% tuning) while achieving a 1-dB bandwidth of 400 MHz. The insertion loss varied from 5.1 dB at zero bias to 3.3 dB at full bias, while the return loss exceeded 13 dB over the range. The third-order intercept of the filter was found to be 41 dBm.     

2 GHz$rm Q$-Enhanced Active Filter With Low Passband Distortion and High Dynamic Range

A tunable$ Q$-enhanced filter with low passband distortion is presented. The$ Q$of the on-chip spiral inductors that form the filter resonators is enhanced by using a cross-coupled differential pair which is degenerated by a second LC tank. This technique allows for frequency dependent compensation of inductor losses and ensures that the$ Q$-enhanced LC resonators have a frequency behaviour close to the ideal in the passband of the filter. The circuit allows DC voltage control of$ Q$-enhancement. The filter centered at 2.0 GHz with a 130 MHz bandwidth is tunable in frequency by 3%, exhibits a$-hbox6.6~dBm$1-dB compression point and a 15 dB noise figure while consuming 17 mW of DC power. The circuit was fabricated in 0.18-$muhbox m$CMOS and the performance was verified experimentally.     

CMOS active-LC bandpass filters with coupled-inductor Q-enhancement and center frequency tuning

A novel CMOS circuit for obtaining a bandpass response from a triple-coupled-inductor arrangement is presented, featuring Q-enhancement and center frequency tuning by means of vector-modulating a current flowing through one of the coupled inductors. A 0.35-/spl mu/m CMOS LC filter prototype employing the technique has been fabricated and exhibits a center frequency tuning range of 11% around 1 GHz and Q values up to 180. The input 1-dB compression point is -13 dBm with Q set to 20 and a power consumption of 12.2 mW. Additionally, an input impedance matching scheme around a spiral transformer is presented, which tracks the center frequency of the filter. The active-LC approach can be applied to higher order filter responses and find applications in tunable building blocks for agile RF front ends and multistandard radios.     

Design of a tapered coaxial resonator filter for mobilecommunications

The authors describe the design, a simple fabrication technique, and performance of a coaxial resonator filter with tapered inner conductors to be used in mobile radios. The effects of coupling, window area, and temperature on the performance of the filter have also been considered. The passband of the filter is 30 MHz with a center frequency of 925 MHz, 1.15-dB insertion loss, 0.8-dB ripple, and 14.7-dB return loss at the center frequency. The resonant frequency and coupling coefficient stabilities with temperature have been measured at 28.38 ppm/°C and 3.5×10^-4/°C, respectively. The 3-dB bandwidth is measured as 32 MHz and a sharp cutoff is observed at -16.5 dB with a bandwidth of 37 MHz for narrow scale and -65 dB with a bandwidth of 84 MHz for wide scale. The fabrication technique developed using a zinc-cast inner conductor and extruded aluminum outer conductor has better reproducibility than the conventional machining technique and is highly cost effective     

The design of a 3-V 900-MHz CMOS bandpass amplifier

A new bandpass amplifier which performs both functions of low-noise amplifier (LNA) and bandpass filter (BPF) is proposed for the application of 900-MHz RF front-end in wireless receivers. In the proposed amplifier, the positive-feedback Q-enhancement technique is used to overcome the low-gain low-Q characteristics of the CMOS tuned amplifier. The Miller-capacitance tuning scheme is used to compensate for the process variations of center frequency. Using the high-Q bandpass amplifier in the receivers, the conventional bulky off-chip filter is not required. An experimental chip fabricated by 0.8-μm N-well double-poly-double-metal CMOS technology occupies 2.6×2.0 mm² chip area. Under a 3 V supply voltage, the measured quality factor is tunable between 2.2 and 44. When the quality factor is tuned at Q=30, the measured center frequency of the amplifier is tunable between 869-893 MHz with power gain 17 dB, noise figure 6.0 dB, output 1 dB compression point at -30 dBm, third-order input intercept point at -14 dBm, and power dissipation 78 mW     

Bandwidth-reconfigurable single-passband microwave photonic filter based on stimulated Brillouin scattering

A bandwidth-reconfigurable filter is necessary to meet the need of growing communication capacity and signal coverage frequency range. The stimulated Brillouin scattering (SBS) gain spectrum as a filter passband is used to extract desired microwave signals. Due to the fact that the passband is formed by mapping the Brillouin gain spectrum, bandwidth reconfigurability can be implemented by changing Brillouin gain linewidth. In this paper, a scheme using a 5-lines optical comb acting as a Brillouin pump is experimentally demonstrated. The spectrum of the 5-lines optical comb is extended by a binary phase shift keying (BPSK) pulse modulated signal. Experiments have shown that the 3-dB and 20-dB bandwidths of the filter are 196 MHz and 257 MHz, respectively, and its 20-dB shape factor is 1.31. The passband ripple is ~3.5 dBm with stop-band rejection of 20 dBm under 15 dBm optical pump power.     

A Novel 3–5 GHz Active Matched Filter for Impulse Radio Ultra-Wideband

In this letter, a novel active matched filter for UWB-IR lower band (3.1–4.85 GHz) is presented. The signal to noise ratio is improved at the output using a tapped delay line with a common source amplifier. An artificial transmission line is used for wideband impedance matching. The matched filter achieves a power gain of 9.8 dB at center frequency. Input matching is better than ${-}19$ dB and output matching is better than ${-}15$ dB. The averaged SNR improvement is 4.6 dB using peak detection. Input referred 1-dB compression point is 0.7 dBm at the center frequency. The matched filter is biased from a 1.5 V supply with a total power consumption of 38 mW.      

A widely tunable continuous-time LPF for a direct conversion DBS tuner

A continuous-time 7th-order Butterworth Gm-C low pass filter (LPF) with on-chip automatic tuning circuit has been implemented for a direct conversion DBS tuner in 0.35μm SiGe BiCMOS technology. The filter's -3 dB cutoff frequency f0 can be tuned from 4 to 40 MHz. A novel on-chip automatic tuning scheme has been successfully realized to tune and lock the filter's cutoff frequency. Measurement results show that the filter has -0.5 dB passband gain, +/- 5% bandwidth accuracy, 30 nV/Hz1/2 input referred noise, -3 dBVrms passband IIP3, and 27 dBVrms stopband IIP3. The I/Q LPFs with the tuning circuit draw 13 mA (with f0 = 20 MHz) from 5 V supply, and occupy 0.5 mm2.     

A 0.6-V 1.6-mW transformer-based 2.5-GHz downconversion mixer with +5.4-dB gain and -2.8-dBm IIP3 in 0.13-/spl mu/m CMOS

On-chip transformers are best suited to lower the supply voltage in RF integrated circuits. A design method to achieve a high current gain with an on-chip transformer operating in resonance is presented. The proposed method will be proven analytically and has been applied to a downconversion mixer. Thereby part of the overall gain of the mixer has been shifted from the RF input stage to the transformer. Thus, the power consumption has been reduced and, in spite of the low supply voltage, moderate linearity has been achieved. Although the transformer has a bandpass behavior, a 3-dB bandwidth of 900 MHz at a center frequency of 2.5 GHz has been achieved. The downconversion mixer has been realized in 0.13-mum CMOS. It consumes 1.6 mW from a 0.6-V supply. A gain of +5.4 dB, a third-order intercept point of -2.8 dBm, an input 1-dB compression point of -9.2 dBm, and a single-sideband noise figure of 14.8 dB have been achieved     

A 1.3-V 5-mW fully integrated tunable bandpass filter at 2.1 GHz in 0.35-/spl mu/m CMOS

A 2.1-GHz 1.3-V 5-mW fully integrated Q-enhancement LC bandpass biquad programmable in f/sub o/, Q, and peak gain is implemented in 0.35-/spl mu/m standard CMOS technology. The filter uses a resonator built with spiral inductors and inversion-mode pMOS capacitors that provide frequency tuning. The Q tuning is through an adjustable negative-conductance generator, whereas the peak gain is tuned through an input G/sub m/ stage. Noise and nonlinearity analyses presented demonstrate the design tradeoffs involved. Measured frequency tuning range around 2.1 GHz is 13%. Spiral inductors with Q/sub o/ of 2 at 2.1 GHz limit the spurious-free dynamic range (SFDR) at 31-34 dB within the frequency tuning range. Measurements show that the peak gain can be tuned within a range of around two octaves. The filter sinks 4 mA from a 1.3-V supply providing a Q of 40 at 2.19 GHz with a 1-dB compression point dynamic range of 35 dB. The circuit operates with supply voltages ranging from 1.2 to 3 V. The silicon area is 0.1 mm/sup 2/.     

A low power high linearity baseband for a direct conversation CMMB tuner

An analog baseband circuit made in a 0.35-μm SiGe BiCMOS process is presented for China Multimedia Mobile Broadcasting (CMMB) direct conversion receivers. A high linearity 8th-order Chebyshev low pass filter (LPF) with accurate calibration system is used. Measurement results show that the filter provides 0.5-dB passband ripple, 4% bandwidth accuracy, and -35-dB attenuation at 6 MHz with a cutoff frequency of 4 MHz. The current steering type variable gain amplifier (VGA) achieves more than 40-dB gain range with excellent temperature compensation. This tuner baseband achieves an OIP3 of 25.5 dBm, dissipates 16.4 mA under a 2.8-V supply and occupies 1.1 mm2 of die size.     

An All-Digital RF Signal Generator Using High-Speed $DeltaSigma$ Modulators

An all-digital RF signal generator using DeltaSigma modulation and targeted at transmitters for mobile communication terminals has been implemented in 90 nm CMOS. Techniques such as redundant logic and non-exact quantization allow operation at up to 4 GHz sample rate, providing a 50 MHz bandwidth at a 1 GHz center frequency. The peak output power into a 100 Omega diff. load is 3.1 dBm with 53.6 dB SNDR. By adjusting the sample rate, carriers from 50 MHz to 1 GHz can be synthesized. RF signals up to 3 GHz can be synthesized when using the first image band. As an example, UMTS standard can be addressed by using a 2.6 GHz clock frequency. The measured ACPR is then 44 dB for a 5 MHz WCDMA channel at 1.95 GHz with output power of -16 dBm and 3.4% EVM. At 4 GHz clock frequency the total power consumption is 120 mW (49 mW for DeltaSigma modulator core) on a 1 V supply voltage, total die area is 3.2 mm² (0.15 mm² for the active area).     

A dual-mode complex filter for GNSS receivers with frequency tuning

A fifth/seventh order dual-mode OTA-C complex filter for global navigation satellite system receivers is implemented in a 0.18 fxm CMOS process. This filter can be configured as the narrow mode of a 4.4 MHz bandwidth center at 4.1 MHz or the wide mode of a 22 MHz bandwidth center at 15.42 MHz. A fully differential OTA with source degeneration is used to provide sufficient linearity. Furthermore, a ring CCO based frequency tuning scheme is proposed to reduce frequency variation. The measured results show that in narrow-band mode the image rejection ratio (IMRR) is 35 dB, the filter dissipates 0.8 mA from the 1.8 V power supply, and the out-of-band rejection is 50 dB at 6 MHz offset. In wide-band mode, IMRR is 28 dB and the filter dissipates 3.2 mA. The frequency tuning error is less than ±2%.     

三阶级联复数有源RC带通滤波器

采用0.18μmCMOS工艺设计了一款应用在无线传网中的三阶级联有源RC复数带通滤波器,同时设计了自动频率调谐电路(AFT)。该滤波器采用的是切比雪夫逼近函数予以实现。在5比特数字控制码开关电容阵列的控制下,AFT电路即可完成对主体滤波器电路频率变化的校正。仿真结果显示,滤波器的中心频率稳定在2MHz,通带带宽为2MHz,镜像抑制比大于34dB,相邻信道阻带衰减大于34dB,通带纹波小于1dB,消耗电流为2.3mA,工作电源电压为1.8V。     

A W-band source module using MMIC's

A W-band source module providing 4-GHz tuning bandwidth (92.5-96.5 GHz) has been developed. This module consists of three MMIC chips: a 23.5 GHz HBT VCO, a 23.5-94 GHz HEMT frequency quadrupler and a W-band three-stage HEMT output amplifier, all fabricated in TRW production lines. It exhibits a measured output power of 3 dBm at 94-95 GHz and a 3-dB tuning bandwidth greater than 3 GHz, with a phase noise of -92 dBc/Hz at 1 MHz offset. This work demonstrates a new and efficient way to implement high performance W-band source. Its wide tuning bandwidth with good phase noise performance, as well as design simplicity, makes this approach attractive for many W-band system applications     

A High Dynamic Range Programmable CMOS Front-End Filter with a Tuning Range from 1850 to 2400 MHz

This paper presents a highly programmable front-end filter and amplifier intended to replace SAW filters and low noise amplifiers (LNA) in multi-mode direct conversion radio receivers. The filter has a 42 MHz bandwidth, is tunable from 1850 to 2400 MHz, achieves a 5.8 dB NF, –25 dBm in-band 1-dB input compression point (ICP) and 0 dBm out-of-band ICP while drawing 26 mA from a 2.5 V supply.     

Analysis and Design of an Integrated Notch Filter for the Rejection of Interference in UWB Systems

A 0.13-mu m CMOS fourth-order notch filter for the rejection of the 5-6 GHz interference in UWB front-ends is reported. The filter is integrated into an analog front-end for Mode #1 UWB. A thorough analysis based on a simplified model of the filter is carried out. An algorithm for the automatic tuning and calibration of the filter is also discussed and demonstrated. Two versions of the circuit are designed and fabricated: the first comprises a low-noise amplifier and the filter, and the second expands it to a complete front-end. In the latter version the filter was also redesigned. The filter provides more than 35 dB of attenuation and has a tuning range of 900 MHz, adding less than 30% power consumption to the LNA. The out-of-band IIP3 (higher than -13.2 dBm with the filter off) takes a 9-dB advantage from the filter and the compression of the gain due to the out-of-band blocker is reduced by at least 6 dB in the complete front-end. The conversion gain of the front-end is 25 dB per channel, its average noise figure is lower than 6.2 dB, and its in-band 1-dB compression point is higher than - 30 dBm at a power consumption of 32 mW.     

A K- to Ka-Band Broadband Doubly Balanced Monolithic Ring Mixer

A broadband doubly balanced monolithic ring mixer with a new intermediate frequency (IF) signal extraction method implemented by 0.15 mum pHEMT process is presented. The hybrid couplers of the proposed mixer consist of multiple coupled lines and fourfold coupled line Marchand baluns. The use of multiple coupled lines leads to a die size less than 1 times 1 mm² and improves the bandwidth of the mixer. The novel fourfold coupled line allows the extraction of the IF signal directly without any extra low pass filter circuits. The mixer exhibited 8-13 dB conversion loss, high radio frequency/local oscillation isolation of 35-50 dB over 16-40 GHz and an input 1-dB compression point of 14 dBm.     

Monolithic transformers and their application in a differentialCMOS RF low-noise amplifier

A 900 MHz low-noise amplifier (LNA) utilizing three monolithic transformers to implement on-chip tuning networks and requiring no external components has been integrated in 2.88 mm² in a standard digital 0.6 μm CMOS process. A bias current reuse technique is employed to reduce power dissipation, and process-, voltage-, and temperature-tracking biasing techniques are used. At 900 MHz, the LNA dissipates 18 mW from a single 3 V power supply and provides 4.1 dB noise figure, 12.3 dB power gain, -33.0 dB reverse isolation, and an input 1-db compression level of -16 dBm. Analysis and modeling considerations for silicon-based monolithic transformers are presented, and it is shown that a monolithic transformer occupies less die area and provides a higher quality factor than two independent inductors with the same effective inductance in differential applications