A Ku-band 100 W power amplifier under CW operation utilizing 0.15 µm GaN HEMT technology

Nagasaka, Masafumi; Nakazawa, Shozo; Tanaka, Shōji; Torii, Takuma; Imai, Shohei; Utsumi, Hiromitsu; Kono, Masaki; Yamanaka, Koji; Fukumoto, Hisao

doi:10.1109/apmc.2016.7931273

Cited by 5 publications

(5 citation statements)

References 4 publications

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“…The LNZ compensates for the AM/AM and AM/PM distortion of the whole PAs [16]. The DA has a saturation power of 60 W and has been reported in detail [15].…”

Section: Sspa Design and Hpa Prototypementioning

confidence: 96%

“…The output power of the HPA becomes higher when a device size characteristic such as the unit gate width (Wgu) becomes larger [15], [16]. In order to increase the output power, the whole transistor needs to be enlarged.…”

Section: Design Of Hpamentioning

confidence: 99%

“…Hence, we set Wgu to 80 µm and used 64cells to have a margin of output power obtaining 30% of PAE. To achieve a higher PAE, we used a second harmonic reflection circuit [15] and set the gate length at 0.15 µm. Figure 8 shows the HPA prototype that we fabricated based on the design in Sect.…”

Section: Design Of Hpamentioning

confidence: 99%

See 2 more Smart Citations

120-W Ku-Band GaN SSPA with Diode Linearizer for Future Broadcasting Satellites

Nagasaka

Kojima

Torii

et al. 2019

IEICE Trans. Electron.

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Satellite broadcasting of 4K/8K ultra-high definition television (UHDTV) was launched in Japan in December 2018. Because this system uses the amplitude and phase shift keying (APSK) modulation scheme, there is a need to improve the non-linear characteristics of the satellite transponders. To meet this requirement, we have been developing a 120-W-class Ku-band solid state power amplifier (SSPA) as a replacement for the currently used traveling wave tube amplifier (TWTA). In this study, we developed a gallium-nitride (GaN) SSPA and linearizer (LNZ). The SSPA achieved an output power of 120 W while maintaining a power added efficiency (PAE) of 31%. We evaluated the transmission performance of 16APSK in this SSPA channel in comparison with that in the TWTA channel.

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“…The LNZ compensates for the AM/AM and AM/PM distortion of the whole PAs [16]. The DA has a saturation power of 60 W and has been reported in detail [15].…”

Section: Sspa Design and Hpa Prototypementioning

confidence: 96%

Section: Design Of Hpamentioning

confidence: 99%

See 1 more Smart Citation

120-W Ku-Band GaN SSPA with Diode Linearizer for Future Broadcasting Satellites

Nagasaka

Kojima

Torii

et al. 2019

IEICE Trans. Electron.

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“…This results in degraded power performance, rather than an optimized output power. Several design techniques are studied and published to resolve this problem [10,11,12,13].…”

Section: Power Amplifier Designmentioning

confidence: 99%

Ku-Band 50 W GaN HEMT Power Amplifier Using Asymmetric Power Combining of Transistor Cells

et al. 2018

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In this paper, we present a Ku-band 50 W internally-matched power amplifier that asymmetrically combines the power transistor cells of the GaN high electron mobility transistor (HEMT) (CGHV1J070D) from Wolfspeed. The amplifier is designed using a large-signal transistor cell model in the foundry process, and asymmetric power combining, which consists of a slit pattern, oblique wire bonding and an asymmetric T-junction, is applied to obtain the amplitude/phase balance of the combined signals at the transistor cell combining position. Input and output matching circuits are implemented using a thin film process on a titanate substrate and an alumina substrate with the relative dielectric constants of 40 and 9.8, respectively. The pulsed measurement of a 330 μs pulse period and 6% duty cycle shows the maximum saturated output power of 57 to 66 W, drain efficiency of 40.3 to 46.7%, and power gain of 5.3 to 6.0 dB at power saturation from 16.2 to 16.8 GHz.

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“…A similar problem has been observed during the development of communication satellites using GaN devices. 1 Research has been conducted to fabricate a vapor chamber using silicon (Si), which is relatively easy to microfabricate via micro-electromechanical system (MEMS) technology. 2−6 To prevent the formation of a thick liquid film on the condensation surface and the uneven distribution of the working fluid, it is necessary to develop a method to effectively eliminate the condensed droplets and liquid film, regardless of the gravity level or gravity vector.…”

Section: ■ Introductionmentioning

confidence: 99%

Dropwise Condensation on a Hierarchical Nanopillar Structured Surface

et al. 2020

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Nanopillar structure processing has been performed on condensation surfaces to control wettability and achieve a high heat transfer coefficient via dropwise condensation and jumping droplets. Modified dry etching was performed using gold (Au) nanoparticles generated by annealing Au as a mask. High-aspect-ratio nanopillar processing was also performed to produce uniform pillar surfaces and novel hierarchical pillar surfaces. A uniform nanopillar surface with pillars having diameters of 20−850 nm and a hierarchical pillar surface with thick pillars having diameters ranging from 100 to 860 nm and thin pillars with diameters ranging from 20 to 40 nm were mixed and fabricated. Condensation experiments were performed using the noncoated nanopillar surfaces, and the condensation behaviors on the silicon (Si) surfaces were observed from above using a microscope and from the side using a highspeed camera. On the uniform surface US-3 and the hierarchical surfaces HS-1 and HS-2, droplet jumps were observed frequently in the droplet size range of 20−50 μm. In contrast, as the droplet size increased to 50 μm or more, the number of jumps observed decreased as the droplet size increased. The frequency of droplet jumps on the hierarchical surfaces from the start of condensation to approximately 2 min was higher than that on the uniform surfaces, although the density of droplet formation on the hierarchical surfaces was not relatively large. On the basis of the observation of droplet behavior from the side surface, we identified that the primary jump was due to the coalescence of droplets adhering to the surface and that the subsequent jump was caused by the droplet coalescence when the jump droplets were reattached. The primary jump occurrence rate was high on all pillar surfaces.

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A Ku-band 100 W power amplifier under CW operation utilizing 0.15 µm GaN HEMT technology

Cited by 5 publications

References 4 publications

120-W Ku-Band GaN SSPA with Diode Linearizer for Future Broadcasting Satellites

120-W Ku-Band GaN SSPA with Diode Linearizer for Future Broadcasting Satellites

Ku-Band 50 W GaN HEMT Power Amplifier Using Asymmetric Power Combining of Transistor Cells

Dropwise Condensation on a Hierarchical Nanopillar Structured Surface

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