NES1823P-100 NEC, NES1823P-100 Datasheet - Page 11

• Manufacturer Part Number: NES1823P-100
• Description: 100W L-BAND PUSH-PULL POWER GaAs MESFET
• Manufacturer: NEC

CIRCUIT DESIGN
substrate. The package-lead impedance is designed as 25
external circuit design, the microstrip line impedance is 25
impedance is connected to balun, it is 1:2 balun structure, finally connected to 50
advantage over single-ended device, minimize matching-loss with decrease of impedance change ratio and cancel
the even mode harmonic frequency for IM
BALUN DESIGN
microstrip balun for this product. What is the reason of our choice? One is the repeatability of assembly, and the
other is its performance. Microstrip balun performance tolerance is small because of its simple structure. So the
balun performance is stable and repeatable between NEC and customers. And its insertion loss is 0.2 dB less than
coaxial balun 0.3 dB, also Its band width is better than coaxial balun. The microstrip balun is consists of microstrip
pattern and cavity, therefore its insertion loss and band width due to its parameter design. Those parameters are
optimized with simuration. : (substrate duroid r = 2.2 t = 0.8 mm)
DC STABILITY (AVOID OSCILLATION)
When the gate is pinch-off, a few pinch-off voltage (VP) difference of each port occur the loop current, then start DC
oscillation in the area of pinch-off. Because of this reasons, the DC-cut capacitor is need to this microstrip balun
assemble. Additionally, the ground of transformer substate is effective to DC oscillation, so that five screws are
arranged at the middle of substrate.
The matching circuit of package inside consists of bond-wire, chip-capacitor and microstrip line on the alumina
The balun design is the key for these high power push-pull structure device. NEC designed low insertion loss
Then the phase difference between two ports is 180° 4, insertion loss is 0.2 dB from 1 to 3 GHz.
The function of DC-cut capacitor arranged between transformer and microstrip balun is avoid DC oscillation.
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performance. The balun circuit is employed for this product.
Preliminary Data Sheet
connecting to the external matching circuit, in the
, conjugate with package impedance, then the
. Balun technology has some
NES1823P-100
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