Sharif Digital Repository

In this thesis, study the design of a compact low-cost integrated time modulated array(TMA). In TMAs, a switch is used instead of a phase shifter, which reduces the area, complexity, power consumption and the final price of the array. The TMAs uses the switch as a control element for array weighting that causes beamforming and beam steering. For the lower cost, designed IC compacted as small as possible and use inexpensive CMOS 180nm technology of TSMC fabrication. Initially, maximum layout size forced 0.7 by 1.5 mm2. The proposed switch type is SPDT that one of its output paths terminated by a matched load and another end to a pad and then by a bond wire connected to an external board that... 

In this thesis, the design of a fully-integrated Millimeter-wave Broadband power amplifier in TSMC 0.18 µm CMOS technology is studied. The Darlington cell with cascode topology was adopted as the power cell to improve the maximum available gain of transistors in standard 0.18 µm CMOS technology to make it eligible of operating at Ka band. Furthermore, by proposing a new topology as an improved Darlington-cascode with intermediate inductor in the Darlington pair, the improvement in flat power gain at Ka band and more importantly, in available power gain of active element at high frequencies of the Ka band is achieved. The proposed power amplifier is a two stage structure with the driver stage... 

In this thesis, two types of smart switch & driver chips are designed in 0.18 um HV BCD technology; low side driver and high side driver. These drivers are smart, because of having various types of protection and detection circuits, which protect switch, driver and connected load, versus errors that can be occurred by the user or other environmental effects. The protection circuits are battery over & under voltage shutdown, current limit, inductive load clamper and thermal shutdown. Load status is checked by status detection circuit and reported to user by one bit flag. Battery voltage can vary from 7 V to 40 V and output current is limited to 2 A. Designed high side and low side drivers are... 

One of the most important parameters of a smartphone is the ability to operate in a long time with a rechargeable battery. As a result, the design of radio frequency circuits which are used in these cell phones is a consistent challenge for designers. Bluetooth Low-Energy standard (BLE) which is the fourth edition of Bluetooth standard is recently introduced with the aim of transporting low volume data with minimum power consumption. The most important challenge of the design of an RF receiver in the BLE standard is the power consumption. In a typical receiver, the oscillator and the mixer are the most power hungry blocks. Therefore, decreasing the power consumption of these two blocks is... 

This thesis begins in an attempt to design an X band front-end receiver in GaAs pHEMT technology, suitable for microwave circuits which should be high frequency, low noise, high gain, as well as high power handling and should have stable characteristics at large number of productions. The front-end receiver consists of three blocks, namely limiter, low noise amplifier, and mixer, which are designed in ISDL group previously. The measurement result of the fabricated low noise amplifier was satisfactory, since it was close to its simulation result. However, due to the drawbacks of modeling the switching behavior of devices, the results of the two other blocks, i.e., limiter and mixer – which... 

A high-Q tunable bandpass filtered amplifier structure is proposed which is based on N-path Q enhancement. Using Fourier series analysis, frequency response of an N-path filter and aliasing effect of this filter is achieved. This effect is caused by frequency translation to bandpass frequency as harmonic fold back (HFB). It is shown that using an additional N-path filter with the same clock frequency but different clock phase HFB is reduced. The conditions for fold back elimination are derived from Fourier series expansions for switched signals. In order to realize HFB reduction and increasing stop-band rejection and Q factor, an LNA associated with N-path filter is added to each of the... 

In this project, an inverting Buck-Boost converter with two negative linear regulator is designed, implemented and measured in CMOS 0.18μm-HV BCD technology. Input voltage of Buck-Boost converter can vary from +15V to +28 and output voltage is digitally adjustable from -1V to -10V. Maximum output current of the converter is 300mA. A current mode controller and a lag compensator is used to control the converter. A high speed highside current sensor is designed and used in current mode controller. Sampled current of the current sensor is also used in a current limit circuitary to limit the maximum current of highside switch. Two negative linear regulators are placed at the output of the... 

In this thesis, a low-power low-phase-noise 28 GHz voltage-controlled oscillator for 5G applications is presented. At first, to select the best structure in terms of FoM, various types of inductors and transformers have been designed and EM simulated. The class-C structure which leads to the highest FoM is chosen eventually. In order to increase oscillation amplitude and reduce phase noise while preserving FoM, a high-frequency noise filter is presented. This filter which is based on a λ/8 microstrip transmission line has solved the conventional filter problems e.g. narrow bandwidth, coupling with oscillator inductor and practical implementation issues.The oscillator is designed, EM... 

The signal sources, based on CMOS technology at mm wave have two categories, the first class is a harmonic oscillator and the second class is fundamental oscillator followed by a frequency multiplier. A systematic approach to obtain the upper bound of efficiency using the activite device condition and, oscillation condition is implemented. Based on polyharmonic distortion at large signal operation, harmonic translation and efficiency are optimized. It is shown that there is an optimum phase for voltage of harmonics at the oscillator ports (the gate and the drain).Based on this analysis, a 300 GHz harmonic oscillator, simulated in TSMC 65nm CMOS is designed. The proposed oscillator has an... 

Voltage Controlled Oscillator (VCO) is one of the essential blocks in communication transceivers. The important specifications of the VCOs like Phase Noise, always is a motivation for researchers in order to introduce novel approaches to conquer these challenges. By development of technology and appearance of new fabrication technologies, this issue take more attention that the past. Also the out of control parameters like process variation and temperature, affect that. So, according to the challenges ahead and the demand of transceiver systems for low phase noise and reasonable power consumption, solutions for overcome these challenges. Finally, a class-C VCO with the tuning range of 4.25-5... 

A novel low noise quadrature voltage-controlled oscillator (QVCO) with differential N-path filter is proposed in 0.18-μm CMOS technology. The said QVCO benefits from a cross-coupled structure and a current-reuse technology to produce the quadrature signal and to save power consumption and area, respectively. The new architecture reduces the phase noise by 8dBc/Hz at a 1MHz offset frequency for 2.4GHz oscillation frequency. QVCO consumes 9.8mW from 1.8V power supply when operating at 2.4GHz. QVCO has a frequency tuning range from 2.4GHz to 3GHz and achieves a FOM of 191dB at 1MHz offset. Switches of N-path filter are controlled by outputs of QVCO, so the center frequency of N-path filter is... 

Thus far numerous components and devices have been designed and realized based on plasmonics. Hereon, we focus on PlasMOStor which is probably the first and most important CMOS compatible plasmonic modulator. It resembles to its electronic counterpart MOS transistor in geometry, unless, it has a plasmonic waveguide instead of the regular channel to modulate optical signals . By applying voltage to the gate and inset of charge carrier accumulation, optical properties of the channel changes and plasMOStor turns off. In this thesis, we carry out a through investigation of plasMOStor’s operation. We show that the proposed theoretical description of plasMOStor is fallacious. Subsequently,... 

In this study, a Local Interconnect Network (LIN) transceiver was designed and implemented. This chip contains transmitter, receiver, low power receiver, digital control unit, oscillator, voltage regulator, high voltage switch, temperature sensor and battery voltage detector. The main focus on this study was on designing transmitter,receiver, low power receiver and temperature sensor. Through designing of this chip, in addition to functional and physical layer specification that mentioned in ISO 17987, electromagnetic compatibility specifications have been considered significantly.The designed chip with slope control and wave shaping of BUS signal has excellent radiated emission performance.... 

The continous growth of wireless networks, the increasing numbers of users and devices, along with the demand for higher data rates have intensified the frequency band limitations as the communication medium. In search for more efficient methods to use this limited resource, the cognitive radio approach that allocates the local unused frequency bands to potential users has attracted considerable attension.
A fundamental and unseperable part of any cognitive radio system is its need to search, detect and understand the surrounding frequency spectrum. Although various methods have been already propose to overcome the challenges of this domain, simpler and more reliable methods are still in... 

CMOS technology has reached two digit nanometer dimensions. This scaling trend improves performance and power consumption on the one hand, and reduces noise margin and circuits reliability on the other. Along with downscaling, sensitivity to radiation induced soft errors is increasing. As CMOS dimensions are shrinking, node capacitance of circuits become smaller. Consequently, particles with smaller charge could induce parasitic voltages in some nodes and result in soft errors. There are more particles with smaller charge than the ones with larger. Therefore, soft error rate is rapidly increasing with technology advances. Single Event Multiple Effects (SEMEs) is a new challenge emerged in... 

According to increasingly utilization of different frequency spots, RF receivers are allways under the threats of compression and desensitization because of large out-of-band or in-band blockers. The IC technologies afford fast, low-resistance switches as scaling keeps going on. With this mind, the Linear Periodic Time Varying circuits, in which the switches play the most dominant role, will be a sensible candidate for the concerns of blocker detection and rejection. Furthermore, nowadays’ receivers should be reconfigureable so as to be tunable at different frequency bands and satisfy contrastive standards. In this regard, the LPTV filters provide vast range of tunablity not only with... 

In order to improve the performance of radar systems, encouraging the movement towards multifunctional applications, wider frequency span is required to be considered for phased array systems constituting radars. The conventional approach of phase shifting is not applicable to wideband phased array system, and the need for phased array systems based on time delay is apparent. In active phased array systems where a transceiver module is placed before each radiating element, the task of controlling the delay and gain variation of each path is assigned to individual core chips residing in the transceiver modules. A typical core chip consists of several amplifying blocks along, with delay and... 

Nowadays, frequency synthesizers are widely used in many modern devices due to the ever-increasing growth of electronic circuits and their applications in various aspects of life. Imaging devices with security applications in the millimeter-wave frequency band is one of the mentioned applications. To prevent crowds at checkpoints and facilitate traffic, these devices need to monitor people's security at the highest possible speed. Furthermore, significant bandwidth is required to increase image quality. Therefore, using frequency generators with high-speed frequency sweep ability is a great advantage. In this thesis, a digital frequency generating chip with 1GHz bandwidth is designed using... 

In this study، a novel frequency multiplier chain for wideband millimeter-wave applications at 28 GHz is presented. Millimeter-wave imaging systems require high frequency and wide bandwidth to accurately detect hidden objects. Various methods have been proposed to increase the frequency of generated signals, but in the meantime، frequency multiplier structures exhibit better performance in terms of bandwidth، power consumption and, harmonic rejection. These circuits are widely used in High-frequency telecommunication systems such as 5th generation mobile services. To design a frequency quadrupler، two multiplier stages based on the improved quadrature Gilbert structure were used. Generating... 

This paper presents a scalable and ultrasensitive magnetic biosensing scheme based on on-chip LC resonance frequency-shifting. The sensor transducer gain is demonstrated as being location-dependent on the sensing surface and proportional to the local polarization magnetic field strength |B|2 generated by the sensing inductor. To improve the gain uniformity, a periodic coil is proposed as a substitution for the standard process coil. As an implementation example, the circuit is designed in a 65nm CMOS process. The spatially uniform sensor gain of the array is verified by COMSOL simulations. Overall, the presented sensor demonstrates an improvement in the uniformity of the inductor’s magnetic...