HARRIS TR-0006-E Portable trunking radio User Manual

HARRIS CORPORATION Portable trunking radio

a href="https://usermanual.wiki/HARRIS" itemprop="url"> HARRIS >

Users Manual

OWDTR-0006-E Exhibit 8 Com-Net Ericsson2.1033 ( c ) 3INSTRUCTION BOOK (DRAFT)SPD-2000 800MHz1. Receiver CircuitThe FM dual-conversion super heterodyne receiver is designed for operation in the 851-870 MHzfrequency range. The Receiver has intermediate frequencies (IF) of 115.65MHz and 450kHz. Adjacentchannel selectivity is obtained by using two band pass filters, a 115.65MHz crystal filter and a 450kHzceramic filter. The RX detector is the phase digitizer.1-1 Receiver Front-endA RF signal from antenna is coupled though the low pass filter/antenna switch, and band pass filter tothe input of low noise amplifier Q101. The output of Q101 is coupled through band pass filter to inputof 1’st Mixer Z101. Front End selectivity is provided by these band pass filter.1-2 1’st MixerThe 1’st Mixer is a Double-Balanced-Mixer Z101, that converts a RF signal the 851-870MHz range to115.65MHz 1’st IF frequency. The signal on the output of Z101 is provided to the input of 1’st IFamplifier Q102.1-3 1’st IFThe 1’st IF signal 115.65MHz from the output of the 1’st Mixer is coupled through 1’st IF amplifierQ102 to Crystal filter FL103. The highly-selective crystal filter FL103 provide the first portion of thereceiver IF selectivity. The output of the filter is coupled through the impedance-matching net work toIF Receiver U101.1-4 2’nd Mixer, 2’nd IF filter and 2’nd IF amplifierIF Receiver U101 is an one-chip IC for digital communication system. It includes 2’nd Mixer, 2’nd IFamplifier and Limiter amplifier. With the internal circuits of U101, The 1’st IF signal is amplified andapplied to the input of 2’nd Mixer. The 2’nd local injection frequency 115.2MHz is applied from 2’ndlocal amplifier Q104 to another input of the 2’nd Mixer. The 2’nd Mixer converts a 1’st IF signal115.65MHz to 2’nd IF frequency 450KHz. Then the 2’nd IF signal is applied to Ceramic FilterFL105(Wide Band) or FL106 (Narrow Band), which provides the 450KHz selectivity. Those IF filtersare controlled by IF.NARROW signal from the microcomputer (HILLARY:U700). The output of the2’nd IF filter is applied through 2’nd IF amplifier and Ceramic Filter FL104(Wide Band) to Limiteramplifier. This IF signal is amplified and balanced outputs, RXIF and RXIF, are sent to HILLARY.These two lines, one positive and the other negative, are used to cancel out any noise that might get onthe line. These balance outputs is applied to the phase digitizer on HILLARY and detected.2, Transmitter CircuitThe Transmitter Circuit consists of Modulator IC (U203), Notch Filter, Variable attenuator (CR201),Buffer Amplifier (U202), Low Pass Filter, PA Module (U201). Automatic Power Control Circuit(Q207, Q201 and U301), Antenna Switch Module (Z302).2-1 Modulator IC and Notch FilterThe main VCO, in the synthesizer circuit, is programmed to generate the TX local Injectionfrequencies (806 to 815 MHz and 851 to 870 MHz). The transmitter carrier frequencies are same ofTX local Injection frequencies.Notch Filter consists of C212, C233, C244, and L210. The output of U203 is applied to Notch Filterthat is through an attenuator pad R204-R206.
OWDTR-0006-E Exhibit 8 Com-Net Ericsson2-2 Variable attenuatorThe output of Notch Filter is applied to Variable attenuator circuit. Variable attenuator circuit consistsof R202, R203, and CR201. The transmitter carrier power is controlled by applying control voltagefrom Power Control Circuit. This control voltage is applied through resistor R203 to the anode ofvariable capacitor CR201 and R202.2-3 Buffer Amplifier and Low Pass FilterThe output of Variable attenuator circuit is applied to the Buffer Amplifier U202 that is amplified to+6dBm. The collector voltage for U202 is provided Switch circuit and is controlled by DPTT.Low Pass Filter consists of C207, C208, C232, and L201. The output of U202 is applied to PA moduleinput through the Low Pass Filter.2-4 PA ModuleThe input of the PA Module is amplified to about 3W. B+ (7.5 V dc) is connected U201 through RFchokes L211. The PA Module consists of two stages RF amplifier. The first stage power supplyvoltage is supplied by power control circuit. The second RF amplifier operates in Class-C. This outputcan be regulated by power control circuit. 2-5 Automatic Power ControlThe Automatic Power Control circuit samples the output power to the antenna to maintain a constantpower level across the band. The Automatic Power Control circuit controls the Vcont voltage to PAModule U201.Directional coupler is include of Antenna Switch Module. Directional coupler provides a sampledsignal of transmit power for diode. Diode produce a positive DC voltage proportional to thetransmitter circuit output power level, that is compared to a comparator (U301) from TX POWERCONT of control unit. The output of U301 is applied to DC amplifier Q207, then the output voltage ofQ207 controls to the Vcont of PA Module for constant output power level.2-6 Antenna Switch ModuleThe Antenna Switch Module consists of switch circuit and the Low Pass Filter.During transmit, DPTT line from HILLARY is high level. Transistor Q205 turns on supply +7.2V toAntenna Switch Module Z302. When transmitting, the Antenna switch diode is low impedance.3. Frequency Synthesizer CircuitIt consists of the Reference Oscillator, PLL Frequency Synthesizer chip U305, Loop filter, Rx VCOZ303, and Tx VCO Z304.PLL Frequency Synthesizer chip receives PLL data, and control information from the microcomputerand from this generates the Tx/Rx RF frequencies. It also provides frequency lock status to themicrocomputer.Rx VCO and Tx VCO are locked to the Reference Oscillator by a single direct-divide synthesis loopconsisting of the Feedback Buffer, Prescaler, and PLL Frequency Synthesizer chip.The Tx VCO operates over a frequency range of 806-825MHz, 851-870MHz.The Rx VCO operates over a frequency range of 735.35-754.35MHz.
Download:
Mirror Download [FCC.gov]
Document ID94597
Application IDldEAkM389rl+dXXh1A5LXA==
Document DescriptionUsers Manual
Short Term ConfidentialNo
Permanent ConfidentialNo
SupercedeNo
Document TypeUser Manual
Display FormatAdobe Acrobat PDF - pdf
Filesize2.38kB (29725 bits)
Date Submitted2000-04-05 00:00:00
Date Available2000-08-21 00:00:00
Creation Date0000-00-00 00:00:00
Producing SoftwareAcrobat Distiller 3.01 for Windows
Document Lastmod2000-04-05 14:58:27
Document TitleUntitled Document
Document CreatorFrameMaker 5.5.3L15a
FCC ID Filing: OWDTR-0006-E

Navigation menu