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OWDTR-0006-E Exhibit 8 Com-Net Ericsson

2.1033 ( c ) 3

INSTRUCTION BOOK (DRAFT)

SPD-2000 800MHz

1. Receiver Circuit

The FM dual-conversion super heterodyne receiver is designed for operation in the 851-870 MHz

frequency range. The Receiver has intermediate frequencies (IF) of 115.65MHz and 450kHz. Adjacent

channel selectivity is obtained by using two band pass filters, a 115.65MHz crystal filter and a 450kHz

ceramic filter. The RX detector is the phase digitizer.

1-1 Receiver Front-end

A RF signal from antenna is coupled though the low pass filter/antenna switch, and band pass filter to

the input of low noise amplifier Q101. The output of Q101 is coupled through band pass filter to input

of 1’st Mixer Z101. Front End selectivity is provided by these band pass filter.

1-2 1’st Mixer

The 1’st Mixer is a Double-Balanced-Mixer Z101, that converts a RF signal the 851-870MHz range to

115.65MHz 1’st IF frequency. The signal on the output of Z101 is provided to the input of 1’st IF

amplifier Q102.

1-3 1’st IF

The 1’st IF signal 115.65MHz from the output of the 1’st Mixer is coupled through 1’st IF amplifier

Q102 to Crystal filter FL103. The highly-selective crystal filter FL103 provide the first portion of the

receiver IF selectivity. The output of the filter is coupled through the impedance-matching net work to

IF Receiver U101.

1-4 2’nd Mixer, 2’nd IF filter and 2’nd IF amplifier

IF Receiver U101 is an one-chip IC for digital communication system. It includes 2’nd Mixer, 2’nd IF

amplifier and Limiter amplifier. With the internal circuits of U101, The 1’st IF signal is amplified an

applied to the input of 2’nd Mixer. The 2’nd local injection frequency 115.2MHz is applied from 2’n

local amplifier Q104 to another input of the 2’nd Mixer. The 2’nd Mixer converts a 1’st IF signal

115.65MHz to 2’nd IF frequency 450KHz. Then the 2’nd IF signal is applied to Ceramic Filter

FL105(Wide Band) or FL106 (Narrow Band), which provides the 450KHz selectivity. Those IF filters

are controlled by IF.NARROW signal from the microcomputer (HILLARY:U700). The output of the

2’nd IF filter is applied through 2’nd IF amplifier and Ceramic Filter FL104(Wide Band) to Limiter

amplifier. 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 on

the line. These balance outputs is applied to the phase digitizer on HILLARY and detected.

2, Transmitter Circuit

The 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 Filter

The main VCO, in the synthesizer circuit, is programmed to generate the TX local Injection

frequencies (806 to 815 MHz and 851 to 870 MHz). The transmitter carrier frequencies are same o

TX local Injection frequencies.

Notch Filter consists of C212, C233, C244, and L210. The output of U203 is applied to Notch Filter

that is through an attenuator pad R204-R206.

Summary of content (4 pages)

PAGE 1
OWDTR-0006-E Exhibit 8 Com-Net Ericsson 2.1033 ( c ) 3 INSTRUCTION BOOK (DRAFT) SPD-2000 800MHz 1. Receiver Circuit The FM dual-conversion super heterodyne receiver is designed for operation in the 851-870 MHz frequency range. The Receiver has intermediate frequencies (IF) of 115.65MHz and 450kHz. Adjacent channel selectivity is obtained by using two band pass filters, a 115.65MHz crystal filter and a 450kHz ceramic filter. The RX detector is the phase digitizer.
PAGE 2
OWDTR-0006-E Exhibit 8 Com-Net Ericsson 2-2 Variable attenuator The output of Notch Filter is applied to Variable attenuator circuit. Variable attenuator circuit consists of R202, R203, and CR201. The transmitter carrier power is controlled by applying control voltage from Power Control Circuit. This control voltage is applied through resistor R203 to the anode of variable capacitor CR201 and R202.
PAGE 3
OWDTR-0006-E Exhibit 8 Com-Net Ericsson -1 Reference Oscillator he reference oscillator consists of a 1.5ppm TCXO (Temperature Controlled Compensated Crystal Oscillator). The standard of reference oscillator frequency is 19.2MHz. he TCXO is enclosed in a RF shielded can. The TCXO is compensated by internal temperature ompensated circuit for both low and high temperature. With no additional compensated the oscillator will rovide 1.5 PPM stability from -30°C to +60°C.
PAGE 4
Safety Information Radio Frequency (RF) Energy Your Com-Net Ericsson transceiver, which radiates RF electromagnetic energy during transmit mode, is designed to comply with the following National and International Standards and Guidelines with regard to RF energy and electromagnetic energy exposure to humans: • • • • • • • IEEE C95.3-1991 published August 21, 1992 FCC OET Bulletin 65 Edition 97-01 NCRP Report No. 119 Issued 1993 FCC Report and Order No.