HMC1197LP7FE datasheet(53/57 Pages) AD

53 / 57 page

For price, delivery, and to place orders: Hittite Microwave Corporation, 2 Elizabeth Drive, Chelmsford, MA 01824

Phone: 978-250-3343

Fax: 978-250-3373

Order On-line at www.hittite.com

Application Support: Phone: 978-250-3343 or apps@hittite.com

HMC1197LP7FE

v03.0314

Wideband direct Quadrature Modulator

w/ Fractional-n Pll & Vco, 100 - 4000 MHz

-70

-60

-50

-40

-30

-20

-10

1000

2000

3000

4000

3rd Harmonic Suppression

2nd Harmonic Suppression

Empirical Band Selection

FREQUENCY (MHz)

Figure 46.Sideband suppression vs. frequency for different filter band selections.

The filter bank selection process for optimal sideband rejection performance also depends on the LO

power level at the output of the PLL/VCO. LO power in this example set to maximum power level.

3.4

carrier Feedthrough calibration

Carrier feedthrough is related to the DC offsets at the differential baseband inputs of the modulator. If

exactly the same DC common-mode voltage is applied to each of the baseband inputs, and there were

no DC offsets at the differential baseband inputs, the LO leakage at the RF output would be perfectly

suppressed.

By adding small DC offset voltages at the differential baseband inputs, the carrier feedthrough can be

optimized for a specific frequency band and LO power level. The carrier feedthrough can not be calibrated

by the DC common-mode level at the I and Q baseband inputs. DC offsets at the differential I and Q

baseband inputs should be iteratively adjusted until a minimum carrier feedthrough level is obtained.

Externally available offset voltage step resolution and the modulator’s noise floor limit the minimum

achievable calibrated carrier feedthrough level. The typical offset voltages for optimization are less than

15mV. Figure 47 illustrates the typical calibrated carrier feedthrough performance of the HMC1197LP7FE. In

this characterization of the HMC1197LP7FE, carrier feedthrough was calibrated with 500MHz LO frequency

steps at 25C and external offset voltage settings were held constant during tests over temperature.

Information furnished by Analog Devices is believed to be accurate and reliable. However, no

responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other

rights of third parties that may result from its use. Specifications subject to change without notice. No

license is granted by implication or otherwise under any patent or patent rights of Analog Devices.

Trademarks and registered trademarks are the property of their respective owners.

For price, delivery, and to place orders: Analog Devices, Inc.,

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106

Phone: 781-329-4700 • Order online at www.analog.com

Application Support: Phone: 1-800-ANALOG-D

HMC1197LP7FE Scheda tecnica(PDF) 53 Page - Analog Devices

HMC1197LP7FE Scheda tecnica(HTML) 53 Page - Analog Devices

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57

Scheda tecnica Scarica

Link URL