5.5-8.4 GHz GaAs MMIC
Voltage Controlled Feedback Oscillator
May 2005 - Rev 05-May-05
9OSC0315
Typical Application (cont.)
A Vector Modulator circuit on the MMIC is a four-quadrant I/Q modulator, and is used to implement the coarse phase delay adjustment. This
circuit allows a 360 degree of adjustment. A key feature of having 360 degrees of phase adjustment is that the VCO can be made to oscillate
at any point where the gain of the rest of the loop exceeds the insertion loss of the filter. This leads to a very flexible architecture in that the
insertion phase of the filter at a given frequency is not important; only the group delay is.
Pr
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Figure 7 shows an example of how quantized phase delays over 360 degrees of phase delay can be set using the vector modulator. The
vector modulator obeys a COS/SIN law for phase adjustment. To sweep over 360 degrees with near uniform spacing as shown in Figure 7,
the control signals would track a full cycle of COS and SIN waves (due to practicalities in the vector modulator implementation, the spacing
won’t be exactly uniform).
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Coarse Phase Adjust
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Mimix Broadband, Inc., 10795 Rockley Rd., Houston, Texas 77099
Tel: 281.988.4600 Fax: 281.988.4615 mimixbroadband.com
Page 7 of 11
Characteristic Data and Specifications are subject to change without notice.
©2005
Mimix Broadband, Inc.
Export of this item may require appropriate export licensing from the U.S. Government. In purchasing these parts, U.S. Domestic customers accept
their obligation to be compliant with U.S. Export Laws.
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