The flotation circuit in Sungun copper plant consists of two column flotation cells as cleaner, having fixed-spargers system. To achieve the expected aims in flotation step, there are serious operational challenges such as: fast choking of the static mixers, boiling problem, burping phenomena and pulp overflow to concentrate lander, maintenance and control problems. An attempt was exerted by im...

Tfds paper explores, experimentally and theoretically, the problem of minimizing secondand third-order intermodulation distortion in diode mixers. A numerical technique is presented which can be used to cakulate internrodulation levels with unprecedented accuracy, and it is used to identify circuit and diode parameters which maximize dynamic range. It is shown that intermorhdation dktortion is ...

This paper describes calibration techniques for downconversion mixers used in integrated direct-conversion receivers. A method of achieving a high even-order intermodulation rejection is presented. Using the method presented, the receiver second-order input intercept point (IIP2) can always be improved by more than 20 dB. The minimum achieved receiver IIP2 after calibration is +38 dBm. A techni...

A compact receiver front-end comprised of subharmonic direct conversion mixers integrated with a planar quasi-Yagi antenna is presented. The front-end generates I and Q baseband outputs, using the quasi-Yagi antenna as a circuit element to split the incoming signal into an I and Q component. Furthermore, the subharmonic design cancels even mixing products, thereby improving even-order distortio...

This paper presents a study of LO selfmixing and RF gain control issues in direct conversion receivers. In cellular systems, that use continuous time frequency duplexing, these can constitute serious problems. The presented topic is of special importance when digitally programmable gain is implemented at the RF frequencies before the downconversion mixers, practically in the LNA. Furthermore, t...

In this paper, I present FPGA implementation of a digital down converter (DDC) and digital up converter (DUC) for a single carrier WCDMA system. The DDC and DUC is complex in nature. The implementation of DDC is simple because it does not require mixers or filters. Xilinx System Generator and Xilinx ISE are used to develop the hardware circuit for the FPGA. Both the circuits are verified on the...

This paper will describe the design and testing of solid-state subharmonically-pumped mixers from 380 GHz to 640 GHz. The main goal has been to develop robust, compact, solid-state room-temperature receivers with state-of-the-art sensitivity and broad IF bandwidths for applications such as airborne and space-based microwave sounding. Testing of a 380 GHz integrated mixer has yielded state-of-th...

This paper introduces a simple yet effective circuit topology to directly generate and modulate UWB pulses using baseband signals. The same circuit can be used to achieve Pulse Position Modulation (PPM), Pulse Amplitude Modulation (PAM), ON-OFF Keying (OOK) and Phase Shift Keying (PSK) by making changes in the baseband data. The method does not require the use of potentially expensive component...

This technical brief provides an overview of communication receiver sensitivity. One of the most important parameters in determining the overall performance of a communication system, receiver sensitivity translates directly into communication distance and reliability. A few receiver architectures can offer dependable communication at low cost, if proper design procedures and trade-offs are imp...

A V-band receiver using a MHMIC multiport circuit is presented in this paper. The millimeterwave frequency conversion is performed using a passive circuit, the multiport, and related power detectors, avoiding the conventional millimeter-wave active costly mixers. Basically, the multiport circuit is an additive mixer in which the resulting sum of millimeter-wave signals is nonlinearly processed ...