Results 311 to 320 of about 281,646 (345)

Frequency Mixer Based on Doppler Effect

IEEE Microwave and Wireless Components Letters, 2018
In this letter, we have proposed and demonstrated a novel mixer that requires no local oscillator (LO), but mixes the radio frequency (RF) with its Doppler shifted frequencies on a nonlinear reconfigurable composite right/left-handed transmission line, on which a moving reflective surface is controlled by an external digital circuit.
Jia Ran, Yewen Zhang, Xiaodong Chen, Hong Chen   +3 more
openaire   +1 more source

Doppler Frequency Geolocation of Uncooperative Radars

MILCOM 2007 - IEEE Military Communications Conference, 2007
Passive geolocation of uncooperative radar emitters remains an important problem in radar electronic warfare. Several location estimation techniques have been investigated in the past. In this paper, we present a passive geolocation technique for radar emitters using Doppler frequency measurements.
B.H. Lee, Y.T. Chan, F. Chan, Huai-Jing Du, Fred A. Dilkes   +4 more
openaire   +1 more source

Frequency agility radar with doppler processing

Electronics and Communications in Japan (Part I: Communications), 1996
AbstractIn the frequency agility radar in which the transmit frequency of the radar can be changed at an ultrahigh speed, not only is excellent electronic counter countermeasure (ECCM) performance obtained but also improvement of the detection probability of the object with a fluctuating reflection cross section is expected.
Seiichi Maeda, Hachirou Sueda, Toshiharu Itoh   +2 more
openaire   +1 more source

CANCELLATION OF DOPPLER FREQUENCY SHIFT

1963
Abstract : A circuit is described which is capable of canceling first-order Doppler frequency shifts. It has potentialities in the fields of communication, data transmission, and navigation systems for vehicles moving at high velocities. The circuit has the following features: (1) Received and transmitted frequencies at each of the stations involved ...
openaire   +1 more source

HPRF pulse Doppler stepped frequency radar

Science in China Series F: Information Sciences, 2009
Stepped frequency radar is a well known scheme to generate high range resolution profile (HRRP) of targets. Through appropriate radar parameter design, the radar enables both unambiguous velocity measurement and high resolution ranging within a single dwell in a high pulse repetition frequency (HPRF) mode.
Teng Long, LiXiang Ren
openaire   +1 more source

A frequency shift maximum frequency follower Doppler demodulator with amplitude correction

Clinical Physics and Physiological Measurement, 1981
A commonly used maximum-frequency follower Doppler demodulator uses a variable-frequency voltage controlled filter that requires two good quality multipliers and can be difficult to set up and stabilise. An alternative presented here has the advantage of cheapness, easy setting-up and amplitude independence over about 25 dB giving the potential for ...
openaire   +2 more sources

Doppler frequency shift of sound apparatus

The Physics Teacher, 2011
A large 1-m diameter rotary table with a semicircular waveguide along its periphery is the basis of the Doppler frequency shift of sound apparatus. A “button” speaker is attached to the outer edge of the rotary table and a microphone pickup is positioned on the wall of the waveguide at its midpoint.
openaire   +1 more source

Cross-frequency Doppler sensitive signal processing

The Journal of the Acoustical Society of America, 2005
When there is relative motion between an acoustic source and a receiver, a signal can be Doppler shifted in frequency and enter or leave the processing bins of the conventional signal processor. The amount of the shift is determined by the frequency and the rate of change in the distance between the source and the receiver.
openaire   +1 more source

Frequency Detuning Control by Doppler Shift

2011
In this work, a control strategy for ship parametric roll resonance is developed by changing the frequency of the parametric excitation. This is achieved by varying the ship’s forward speed. This changes the perceived frequency of the waves, known as the encounter frequency (and thus the frequency of parametric excitation), via Doppler shift.
Christian Holden, Dominik A. Breu, Thor I. Fossen   +2 more
openaire   +1 more source

Joint Estimation of Doppler Frequency Shift and Doppler Frequency Rate Based on Interpolation

Journal of Electronics & Information Technology, 2014
Wei Jiang, Tian Le
openaire   +1 more source