OPT002: Standard Carrier Path Attenuator This is similar to OPT001 but the attenuator will briefly break circuit when changing amplitude potentially causing the system to lose lock. This attenuator is less costly so if losing lock is not a concern, than this may be preferable. This option does allow for reverse E_b/N_o setting. This option is commonly used for R&D and qualification where it may be desired to run waterfall curves over several different amplitude ranges. This option is also selected as purely a convenience if in the overall test system if there are no other ways to adjust the signal path amplitude.

OPT003: Zero Carrier Path Loss This option utilizes a high 3rd order intercept, low distortion amplifier in the signal though path to make up for the insertion loss. This loss is caused by a combination of the path components which includes the coupler which sends a portion of the signal to the power meter, the combiner which adds noise to the signal, the attenuator (if ordered) and the impedance transformer (if ordered). The magnitude of the loss is from 5 to 12 dB depending on the model and option package ordered. Generally, if the loss does not pose a problem, this option should probably not be ordered. Despite the high quality amplifier used, it is not generally recommended to have any unnecessary active devices in the test signal path.

OPT004: Coupled Carrier Path Low Noise Amplifier This option calls out a low noise amplifier in the coupled carrier path. This does not affect the test signals through path. It is selected if weak signal levels will be used going into the CNG carrier input port. The embedded power meter in the CNG units can accurately measure input signals corresponding to an optional input range of about from -30 dBm to -7 dBm. This option boosts the coupled signal path 30-35 dB for an accurate input range of -12 dBm to -62 dB, and is typically selected for mobile telecom or terrestrial radio applications in which the noise is added to the RF signal. This is opposed to satellite modem loop back testing in which the noise is injected at IF, such as at 70/140 MHz. Mobile telecom test protocols typically use weaker signals (from -25 to -60 dBm). In addition noise is often added after multi-path fading simulation such as in the case of IS-95 or 3GPP CDMA phone/base-station receive testing.

OPT004A: Coupled Carrier Path LNA Bypass Switch This option is selected to increase the dynamic range of the input signal. It is only ordered if OPT004 is also ordered. It allows signals to be accurately measured from -62 to +10 dBm. The default switch position is in the bypass state.

OPT005: Interfering Signal Input for C/I Mode This mode allows the user to set C/I ratios as well as C/N or E_b/N_o ratios. The interfering signal is generated externally and connected to the injector input port of the CNG. When selected, a transfer switch substitutes the interference signal for the noise signal. This option is typically not used in Satellite applications but is sometimes used in mobile telecommunications where the interfering signal simulates adjacent channel interference. This option has been offered as standard traditionally and was included in the now obsolete HP3708A. However, in our market survey, we found most programs did not require this feature, so we decided to make it optional.

OPT006: Impedance 75 Ohm impedance instead of 50 Ohm.

OPT006A: Switchable Impedance 75 Ohm impedance/50 Ohm impedance swtichable.

OPT007: RS/232 Interface This option allows the CNG to be operated remotely using an RS/232 serial connect

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