1,180 research outputs found
Hardware simulation of Ku-band spacecraft receiver and bit synchronizer, volume 1
A hardware simulation which emulates an automatically acquiring transmit receive spread spectrum communication and tracking system and developed for use in future NASA programs involving digital communications is considered. The system architecture and tradeoff analysis that led to the selection of the system to be simulated is presented
A 24-GHz SiGe Phased-Array ReceiverâLO Phase-Shifting Approach
A local-oscillator phase-shifting approach is introduced to implement a fully integrated 24-GHz phased-array receiver using an SiGe technology. Sixteen phases of the local oscillator are generated in one oscillator core, resulting in a raw beam-forming accuracy of 4 bits. These phases are distributed to all eight receiving paths of the array by a symmetric network. The appropriate phase for each path is selected using high-frequency analog multiplexers. The raw beam-steering resolution of the array is better than 10 [degrees] for a forward-looking angle, while the array spatial selectivity, without any amplitude correction, is better than 20 dB. The overall gain of the array is 61 dB, while the array improves the input signal-to-noise ratio by 9 dB
Design of a tunable multi-band differential LC VCO using 0.35 mu m SiGe BiCMOS technology for multi-standard wireless communication systems
In this paper, an integrated 2.2-5.7GHz multi-band differential LC VCO for multi-standard wireless communication systems was designed utilizing 0.35 mu m SiGe BiCMOS technology. The topology, which combines the switching inductors and capacitors together in the same circuit, is a novel approach for wideband VCOs. Based on the post-layout simulation results, the VCO can be tuned using a DC voltage of 0 to 3.3 V for 5 different frequency bands (2.27-2.51 GHz, 2.48-2.78 GHz, 3.22-3.53 GHz, 3.48-3.91 GHz and 4.528-5.7 GHz) with a maximum bandwidth of 1.36 GHz and a minimum bandwidth of 300 MHz. The designed and simulated VCO can generate a differential output power between 0.992 and -6.087 dBm with an average power consumption of 44.21 mW including the buffers. The average second and third harmonics level were obtained as -37.21 and -47.6 dBm, respectively. The phase noise between -110.45 and -122.5 dBc/Hz, that was simulated at 1 MHz offset, can be obtained through the frequency of interest. Additionally, the figure of merit (FOM), that includes all important parameters such as the phase noise, the power consumption and the ratio of the operating frequency to the offset frequency, is between -176.48 and -181.16 and comparable or better than the ones with the other current VCOs. The main advantage of this study in comparison with the other VCOs, is covering 5 frequency bands starting from 2.27 up to 5.76 GHz without FOM and area abandonment. Output power of the fundamental frequency changes between -6.087 and 0.992 dBm, depending on the bias conditions (operating bands). Based on the post-layout simulation results, the core VCO circuit draws a current between 2.4-6.3 mA and between 11.4 and 15.3 mA with the buffer circuit from 3.3 V supply. The circuit occupies an area of 1.477 mm(2) on Si substrate, including DC, digital and RF pads
Architectures for RF Frequency synthesizers
Frequency synthesizers are an essential building block of RF communication products. They can be found in traditional consumer products, in personal communication systems, and in optical communication equipment. Since frequency synthesizers are used in many different applications, different performance aspects may need to be considered in each case. The main body of the text describes a conceptual framework for analyzing the performance of PLL frequency synthesizers, and presents optimization procedures for the different performance aspects. The analysis of the PLL properties is performed with the use of the open-loop bandwidth and phase margin concepts, to enable the influence of higher-order poles to be taken into account from the beginning of the design process. The theoretical system analysis is complemented by descriptions of innovative system and building block architectures, by circuit implementations in bipolar and CMOS technologies, and by measurement results. Architectures for RF Frequency Synthesizers contains basic information for the beginner as well as in-depth knowledge for the experienced designer. It is widely illustrated with practical design examples used in industrial products.\ud
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Electrical and electronic engineer
ULTRA-LOW-JITTER, MMW-BAND FREQUENCY SYNTHESIZERS BASED ON A CASCADED ARCHITECTURE
Department of Electrical EngineeringThis thesis presents an ultra-low-jitter, mmW-band frequency synthesizers based on a cascaded
architecture. First, the mmW-band frequency synthesizer based on a CP PLL is presented. At the
first stage, the CP PLL operating at GHz-band frequencies generated low-jitter output signals due
to a high-Q VCO. At the second stage, an ILFM operating at mmW-band frequencies has a wide
injection bandwidth, so that the jitter performance of the mmW-band output signals is determined
by the GHz-range PLL. The proposed ultra-low-jitter, mmW-band frequency synthesizer based on
a CP PLL, fabricated in a 65-nm CMOS technology, generated output signals from GHz-band
frequencies to mmW-band frequencies, achieving an RMS jitter of 206 fs and an IPN of ???31 dBc.
The active silicon area and the total power consumption were 0.32 mm2 and 42 mW, respectively.
However, due to a large in-band phase noise contribution of a PFD and a CP in the CP PLL, this
first stage was difficult to achieve an ultra-low in-band phase noise. Second, to improve the in-band
phase noise further, the mmW-band frequency synthesizer based on a digital SSPLL is presented.
At the first stage, the digital SSPLL operating at GHz-band frequencies generated ultra-low-jitter
output signals due to its sub-sampling operation and a high-Q GHz VCO. To minimize the
quantization noise of the voltage quantizer in the digital SSPLL, this thesis presents an OSVC as a
voltage quantizer while a small amount of power was consumed. The proposed ultra-low-jitter,
mmW-band frequency synthesizer fabricated in a 65-nm CMOS technology, generated output
signals from GHz-band frequencies to mmW-band frequencies, achieving an RMS jitter of 77 fs
and an IPN of ???40 dBc. The active silicon area and the total power consumption were 0.32 mm2 and
42 mW, respectively.clos
Design of CMOS integrated frequency synthesizers for ultra-wideband wireless communications systems
UltraÂŹwide band (UWB) system is a breakthrough in wireless communication, as it provides data rate one order higher than existing ones. This dissertation focuses on the design of CMOS integrated frequency synthesizer and its building blocks used in UWB system.
A mixerÂŹbased frequency synthesizer architecture is proposed to satisfy the agile frequency hopping requirement, which is no more than 9.5 ns, three orders faster than conventional phaseÂŹlocked loop (PLL)ÂŹbased synthesizers. Harmonic cancelaÂŹtion technique is extended and applied to suppress the undesired harmonic mixing components. Simulation shows that sidebands at 2.4 GHz and 5 GHz are below 36 dBc from carrier. The frequency synthesizer contains a novel quadrature VCO based on the capacitive source degeneration structure. The QVCO tackles the jeopardous ambiguity of the oscillation frequency in conventional QVCOs. Measurement shows that the 5ÂŹGHz CSDÂŹQVCO in 0.18 ”m CMOS technology draws 5.2 mA current from a 1.2 V power supply. Its phase noise is ÂŹ120 dBc at 3 MHz oïŹset. Compared with existing phase shift LC QVCOs, the proposed CSDÂŹQVCO presents better phase noise and power eïŹciency.
Finally, a novel injection locking frequency divider (ILFD) is presented. Implemented with three stages in 0.18 ”m CMOS technology, the ILFD draws 3mA current from a 1.8V power supply. It achieves multiple large division ratios as 6, 12, and 18 with all locking ranges greater than 1.7 GHz and injection frequency up to 11 GHz. Compared with other published ILFDs, the proposed ILFD achieves the largest division ratio with satisfactory locking range
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