User`s guide
Chapter 1 31
Signal Generator Overview
Rear Panel
39. I IN
This female BNC input connector (E8267D only) accepts the in- phase (I) component an externally 
supplied, analog, I/Q modulation. The quadrature- phase (Q) component is supplied through the Q IN 
connector. The signal level is   = 0.5 V
rms
 for a calibrated output level. The nominal input 
impedance is 50 or 600 ohms. The damage level is 1 V
rms
 and 10 V
peak
. To activate signals applied to 
the I and Q input connectors, press 
Mux > I/Q Source 1 or I/Q Source 2 and then select either Ext 50 Ohm or 
Ext 600 Ohm. On signal generators without Option 1EM, this connector is located on the front panel.
40. SYMBOL SYNC
This female BNC input connector (E8267D only) is CMOS- compatible and accepts an externally 
supplied symbol sync signal for use with the internal baseband generator (Option 601/602). The 
expected input is a 3.3 V CMOS bit clock signal (which is also TTL compatible). SYMBOL SYNC might 
occur once per symbol or be a single one-bit-wide pulse that is used to synchronize the first bit of 
the first symbol. The maximum clock rate is 50 MHz. The damage levels are > +5.5 V and < −0.5V. 
The nominal input impedance is not defined. SYMBOL SYNC can be used in two modes:
• When used as a symbol sync in conjunction with a data clock, the signal must be high during the 
first data bit of the symbol. The signal must be valid during the falling edge of the data clock 
signal and may be a single pulse or continuous.
• When the SYMBOL SYNC itself is used as the (symbol) clock, the CMOS falling edge is used to 
clock the DATA signal.
On signal generators without Option 1EM, this connector is located on the front panel.
41. Q IN
This female BNC input connector (E8267D only) accepts the quadrature- phase (Q) component an 
externally supplied, analog, I/Q modulation. The in- phase (I) component is supplied through the I IN 
connector. The signal level is   = 0.5 V
rms
 for a calibrated output level. The nominal input 
impedance is 50 or 600 ohms. The damage level is 1 V
rms
 and 10 V
peak
. To activate signals applied to 
the I and Q input connectors, press 
Mux > I/Q Source 1 or I/Q Source 2 and then select either Ext 50 Ohm or 
Ext 600 Ohm. On signal generators without Option 1EM, this connector is located on the front panel.
42. DATA
This female BNC input connector (Option 601/602 only) is CMOS compatible and accepts an 
externally supplied serial data input for digital modulation applications. The expected input is a 3.3 V 
CMOS signal (which is also TTL compatible) where a CMOS high = a data 1 and a CMOS low = a data 
0. The maximum input data rate is 50 Mb/s. The data must be valid on the falling edges of the data 
clock (normal mode) or the on the falling edges of the symbol sync (symbol mode). The damage levels 
are > +5.5 and < −0.5V. The nominal input impedance is not defined. On signal generators without 
Option 1EM, this connector is located on the front panel.










