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TDD is one of the duplex technologies used by the mobile communication system, and its role is to separate the receiving and transmitting channel (the uplink or downlink). This paper presents a high speed TDD baseband data processing system realized on the FPGA. Through the data transceiver loop method, it's verified that the transceiver switching rate of the TDD mode can be 8KHZ and the data transfer...
This paper describes in detail how to select components of the peripheral circuits of LT3748. In this paper, the LT3748 is introduced to produce an 8Vout at 3A from the nominal input voltage −48V with an operating input voltage range of −38.4V to −72V, where −48V is a common telecommunications equipment voltage. The test results show the output voltage and the current meet the demand of the project...
As the development of wireless communication, people put forward higher requirements on wireless transceiver system. MIMO technology is a major breakthrough in the field of wireless communication and it can greatly increase the channel capacity and spectrum efficiency without expanding bandwidth. This paper works on the design, development and test of a MIMO transmitter which supports four transmit...
This paper presents a wide-band receiver at 2.4GHz and 5GHz for 4×4 MIMO wireless communication system. This design is proposed and realized using super heterodyne architecture solution. Dual conversion structure is used in this receiver system. The receiver benefits from RF part, control part and phase shifter part. The carrier of this transceiver is 1.82GHz and 4.42GHz, and the local oscillation...
Co-Channel Dual Polarization (CCDP) technology is an efficient way to double the link capacity in modern communication system. However, the consequent polarization interferences become an inevitable problem to fight. Therefore, a Cross-Polarization Interference Canceller (XPIC) is necessary against the cross-talks. This paper focuses on the baseband XPIC technology and builds a simulink model to show...
Nowadays, the 24GHz band is allowed temporarily for car radars by European Telecommunication Standards Institute (ETSI) until 2013, when the hardware technology (MMICs, antennas, etc.) will be mature enough to enable the development and production of automotive radar modules at the 76–81 GHz band. In this paper, a common structure of homodyne LFMCW (Liner Frequency Modulated Continuous Wave) radar...
In the system of a communication, the control segment of the system is of great significant, it determines that whether the system can be work normally directly. The control system of a system can control the on-off of the power, the LO frequency of the system that controlled by code, and the switch, and the VGA that controlled by digit, all of what are the key figures of a communication system. In...
In this paper, a Ka band broadband bandpass filter with substrate integrated waveguide (SIW) technology is presented and investigated with simulation and experiment, which can provide 32.7% fractional bandwidth at the center frequency of 35GHz. In order to connect with microstrip circuits, an SIW to microstrip transition is included in this design. Simulation results, which are in agreement with measurement...
This paper proposes a new transform called simplified linear canonical transform (SLCT) that provides a new method for parameter estimation of linear frequency-modulated (LFM) chirp signals embedded in additive white Gaussian noise. The proposed transform is a linear transform and has a more succinct form as compared with the fractional Fourier transform (FRFT). The discrete SLCT with fast Fourier...
In this paper, a novel multiple-tunable frequency synthesizer structure to achieve both high frequency resolution and fast switching speed without degradation of spurious performance is proposed. According to this structure, a high performance millimeter-wave frequency synthesizer with low spurious, low phase noise, and fast switching speed, is developed. This synthesizer driven by the direct digital...
This paper gives a brief overview of voltage controlled oscillator(VCO) based on Si CMOS and SiGeBiCMOS process technologies. The status of designing techniques for high performance VCO is summarized because of its importance for high-speed communication systems and radar sensors. Then, the development tendency of VCO is introduced.
Aimed at the problem of the near-field imaging in real time, a near-field narrow 2-D imaging algorithm based on the combination of single-input multiple output array (SIMO) and synthetic aperture radar (SAR) is proposed. By combining a real aperture and synthetic aperture, a 2-D synthetic aperture plane which is in terms of spatial sampling to obtain the target scattering information is synthesized...
Waveguide T-junction and directional couplers are widely used in microwave/millimeter wave systems, because its circuit is simply and easily to be designed and fabricated. In this paper, a ka-band E-plane rectangular waveguide power divider is proposed and optimized. The first level of the network is the T-junction, which can halve the power for the first time, and the second level are two 3dB directional...
This paper proposes an improved 1 to 4 power divider based on oversized-coaxial and radial waveguide. To widen the bandwidth of the divider/combiner, an axially symmetric oversized coaxial waveguide is used to transform input to the radial waveguide, and at the bottom of the radial waveguide, stepped-impedance technology is used to realize the impedance match. According to EM simulations, the simulated...
This paper presents a 65–85 GHz 5-bit passive phase shifter at the desired frequency of 77 GHz, using CMOS switches available in the 0.13 µm SiGe BiCMOS process. The phase shifter is based on a low-pass π-network and CMOS passive transistors. The RMS phase error, the insertion loss and the VSWR is less than 3.5°, −20 dB and 2 at 77 GHz respectively, so it is possible to precede this design with a...
In this paper, two classes of Ka-band Substrate Integrated Waveguide(SIW) power divider are presented and studied. The advantages of the SIW technique are its low profile, low-lost, mass-productive, ease of fabrication and fully integrated with planar circuits. All the modules are designed to be operated in a wide frequency range. The Y-junction shows a bandwidth of 29.4%.
The paper firstly studies two novel power-dividing structures which are used in solid-state power amplifiers. Two structures are similar to each other except the air holes. According to the EM simulation, the return loss of first one is smaller than −20dB in the required bands, and the second about −25dB. This paper researches the difference of two structures, and gives the reason which causes the...
Spurious frequencies (spurs) resulting from phase truncation are one of the main spectrum purity issues for direct digital synthesizers (DDS). The standard approach in DDS design consists of truncating the phase word output from the phase accumulator in order to minimize the size of the lookup table. This process generates spurs and degrades the quality of signals at the output of a DDS. The truncation...
In this paper, an approach of developing high agility and resolution millimeter-wave synthesizer architecture without using PLL (Phase Locked Loop) is proposed. Using the frequency multiplying of DDS output signal to provide the local oscillators instead of PLL in traditional three frequency conversions scheme, with good frequency configuration and optimal utilization of DDS (Direct Digital Synthesizer),...
We investigate the parameter estimation problem of polynomial phase signals with time-varying amplitudes. For many models of polynomial phase signals with time-varying amplitudes, the parameters can be expressed by the coefficients of its finite-order Taylor series expansion. And the estimation of phase and amplitude parameters can be converted to the estimation of the Taylor coefficients. We propose...
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