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The existing directions-of-arrival (DOAs) estimation methods for two-dimensional (2D) coherently distributed sources need one- or two-dimensional search, and the computational complexities of them are high. In addition, most of them are designed for special angular signal distribution functions. As a result, their performances will degenerate when deal with(More)
In this paper, the resonant frequency and sensitivity characteristics of Hilbert curve fractal antennas is presented. Several fractal-shaped Hilbert monopoles have been constructed, based on theoretical calculation, EM simulation and measurement. The formulation on resonant frequency of the Hilbert antennas is derived and verified. Experimental results show(More)
A novel low-loss image-reject mixer (IRM) using the source follower isolation method for digital radio mondiale/digital audio broadcasting applications is presented. It is based on double-quadrature mixers (DQMs) and passive polyphase filters (PPFs). The DQM is designed with four passive CMOS mixers. A source follower is inserted between the RF PPF and DQM(More)
the paper presents the design of a high-speed wideband low phase noise 2:1 frequency divider. A new differential D-latch topology for the divider is presented. Theoretical analysis and an optimization process for the design are given and various phenomena that dominate the speed, the bandwidth and the phase noise behavior of the frequency dividers are(More)
A surface-acoustic-wave-less first folded-conversion and second down-conversion receiver for the AM/FM/digital radio mondiale (DRM)/digital audio broadcasting (DAB) radio standards is presented. This architecture is more suitable for broadcasting radio with ultra-narrow signal bandwidth since it relaxes the requirement on the local area (LO) generator by(More)
In this paper, A Software-Defined Radio (SDR) RF front-end is presented that contains LNA, mixers, VGAs, and frequency synthesizer, supporting various wireless communication standards in 0.1–2 GHz while guaranteeing a power/performance trade-off at any time. The circuit is fabricated in a 0.18 µm RF CMOS technology with 1.8 V supply voltage.(More)
The implementation of a high-speed low-power pulse swallow frequency divider for a DRM/DAB frequency synthesizer, using a 0.18-μm CMOS technology, is described. The frequency divider employs a divide-by-32/33 dual-modulus prescaler, a five bits swallow counter, an 11 bits programmable counter, and a control circuit necessary for the time sequence and(More)
Design of system for wireless commutation and data acquisition and transplant method of embedded real-time operating system on DSP are mainly researched. The difficulties of transplant and multi-task acquisition and communication of synchronous signal are resolved. And after transplant, the system is scaled. The transplant and boot loader are both burned on(More)
This paper presents skills to reduce the detection time and assure the frequency grid of the automatic frequency detector circuit in a DRM/DAB receiver. To support minimum receiver requirements for DRM ldquoDraft Version 1.21rdquo, we introduce an automatic frequency detector (AFD) technique for the low-IF receiver, which uses a new detect algorithm to(More)
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