A low noise active down converting mixer using quiescent current injection technique. The sinusoidal local oscillator signal is used to drive to avoid the noise superposition induced by the pulse ballast harmonics; the LC resonant structure is used to replace the resistance load of the traditional Gilbert unit to relieve the limitation of the charging and discharging of the parasitic capacitance of the tail node on the high-frequency operation of the circuit. The proposed mixer is implemented in a 65 nm CMOS process, with a working range of 0.2-2.2 GHz double-sideband noise figure with a maximum noise figure of 5 dB, and a minimum noise of 4.44 dB at the inflection point at 800 MHz. Working in the RF frequency band of 1GHz, the maximum voltage gain is 25dB, and the maximum 1dB compression point is -7.2dB, maximum IIP3 is 13 dB.
The Bridges had collapsed accidents in recent years due to bridges quality problems. Therefore, concretes nondestructive testing are particularly important. At present, most applications are Ground Penetrating Radar (GPR) technology in the detection of reinforced concretes structure. GPR are used the pulse method which alongside with definitive advantages, but the testing of the internal structure of the small thickness concretes has very low resolution by this method. In this paper, it’s the first time to use the ultra-wideband (UWB) stepped frequency conversion radar above problems. We use vector network analyzer and double ridged horn antenna microwave imaging system to test the reinforced concretes block. The internal structure of the concretes is reconstructed with a method of synthetic aperture of ω-k algorithm. By this method, the depth of the steel bar with the diameter of 1cm is shown exactly in the depth of 450mm×400mm×500mm and the depth error do not exceed 1cm.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.