if the worker can complete the tense production task of Cell Phone Jammers

The Cell Phone Jammers company decides to hold the ribbon –cutting ceremony.
Antenna switching circuit are generally integrated circuit and external components, such as the Motorola P7689 cell phone on the use of this approach, mainly by the U150, U151 and associated external components shown in Figure 4-4. The antenna switch circuit There are three main roles: for built-in antenna and external antenna ANTl EXT-ANT switch; for the transceiver to switch; for receipt of the letter 1800MHz, 900MHz, 1900MHz switch. External antenna connection from the bottom of the socket J600 provides the first 2 feet, which, INT-2 is prepared to receive 1800MHz band signal output, 1NT-3 is prepared to receive the 900MHz and 1900MHz frequency band signal output, RX275-DCS is the DCS band control signal, RX275- GSM-PCS is GSM, PCN band control signal, all from the CPU; TXIN for the transmit signal input, RF-V1 is the power switch for the transceiver, TXON allowed to transmit signals, RX-0N to receive the enable signal, FILTERED negative power.
Low-noise amplifier in the antenna circuit is mainly sensitive to the weak RF signal amplification in order to meet the mixer input signal amplitude requirements. In the cell phone circuit diagram, the low noise amplifier is the abbreviation of LNA (Low Noise Amplifier). Receiver low-noise amplifier is the first stage amplifier circuit, the circuit is located after the antenna. Before and after the low noise amplifier, RF filters usually have. Low-noise amplifier is a high-frequency small-signal amplifier, the amplifier transistor requires a high cutoff frequency, magnification, noise coefficient. The first-level signal is very small, lower than the operating point is usually set at the same time plus current negative feedback, reducing the noise. High-frequency amplifier circuit using low-noise amplifier can improve the overall receiver noise figure. While high-frequency amplifier also prevent RXVCO signal radiated from the antenna path. The general manager promises that the bonus will be higher if the worker can complete the tense production task of Cell Phone Jammers .
Discrete low-noise amplifiers are usually in a common emitter circuit, to the weak RF signal amplification and offset caused by the RF filter insertion loss. In the low-noise RF transistor amplifier, low noise performance from the start, its bias or bias supply filter through the supply of electrical resistance, this can avoid power supply noise and bias resistor thermal noise introduced into the RF channel, the impact amplifier noise performance. Figure 4-7 Motorola P7689 phone GSM900 low-noise amplifier circuit. In the circuit, low-noise amplifier transistor Q400 is the core of the device. Q400 and the surrounding components together constitute the GSM900 low-noise amplifier. Which is the input capacitance C402, C405 is the collector output capacitance. LA02, R401, C403 and so together constitute a reactance filter power supply circuit, the RX-275-GSM power supply filtering, and then to the Q400's collector power. The inspection report of Cell Phone Jammers needs the signature of the director of Cell Phone Jammers workshop.