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CTA Communications <br />Orange RaCE Test Report <br />Both talk -in and talk -out directions must be adjusted to account for the differences in <br />gain /losses between these two different configurations. Different attenuation factors for <br />talk -out and talk -in are achieved by using a circulator in the RaCE mobile unit antenna <br />feed line as shown in FIGURE 6 -2. The values for the attenuators are shown in this <br />figure and calculated as follows. <br />In the RaCE mobile unit talk -out direction, attenuation is needed to account for the <br />difference in receive sensitivity of the test mobile and the receiver sensitivity of the typical <br />portable, as well as the difference in the antenna losses for these two different <br />configurations. We first select the amount of attenuation (Attenuator #1) needed to <br />simulate the corrected talk -out attenuation required. This value is calculated to be 6.5 dB <br />and a commonly available 6 dB attenuator was used for this purpose. The loss through <br />the circulator of approximately 0.6 dB is factored into the calculations, and the test set -up <br />talk -out correction is calculated to be 6.6 dB including the loss for the circulator. TABLE <br />64 summarizes the calculation of attenuation needed for the RaCE mobile unit talk -out <br />correction to simulate the typical portable operational configuration. <br />The next step is to calculate the attenuation needed for the RaCE mobile unit talk -in <br />correction, taking into consideration the difference in test mobile transmitter power and <br />typical portable transmitter power, as well as the difference in antenna system losses <br />between these two configurations. This value was calculated to be 15.7 dB. As shown in <br />FIGURE 6 -2, this is comprised of the series of Attenuators #1, Attenuator #2 and the <br />circulator. An additional 9.1 dB of attenuation is needed and two commonly available <br />attenuators totaling 9.3 dB of attenuation was utilized. TABLE 6 -5 summarizes the <br />calculation of the attenuation needed for the RaCE mobile unit talk -in correction to <br />simulate the typical portable operational configuration. <br />Ttshin a-A Mnhilp unit Talk -Out Correction For Portable Receive <br />Receiver Sensitivity <br />Portable <br />Mobile <br />Antenna System Losses <br />Portable Talk -Out Antenna System <br />Total for at the Hip <br />Mobile Talk -Out Antenna System <br />Mobile Antenna <br />Mobile Coax <br />Circulator <br />Total for Mobile Talk -Out Antenna <br />-119.0 dB <br />-119.0 dB <br />Sensitivity Difference -0 dB <br />0.0 dB <br />1.9 dB <br />0.6 dB <br />•o <br />2.5 dB <br />Antenna System Loss Difference 6.5 dB <br />Total Talk -Out Correction Attenuation 6.5 dB <br />Test Set -Up Talk -Out Attenuation (per FIGURE 3 -2) _ <br />(Attenuator #1 + Circulator) <br />Attenuator #1 selected to be 6 dB <br />Test Set -Up Talk -Out Attenuation is (Attenuator #1 + Circulator) 6.6 dB <br />-17- <br />H MM I AECOM <br />