InP FOR PAs InP Provides Improved Low Voltage Wireless PA Performance

I s history about to repeat itself in the wireless power amplifier industry with indium phosphide (InP) replacing the now dominate gallium arsenide (GaAs) semiconductor material just as GaAs replaced silicon for power amplifiers in the 1990s? There are a few companies that are currently exploring this avenue by commercializing InP for the wireless industry. InP is not a new technology. It is currently utilized in military and photonics with thousands of wafers fabricated per year. However, this pales in comparison to GaAs with high volume ODM fabs pushing a hundred thousand or more wafers each year. Smaller ODM fabs are not at this level, but, total GaAs wafer quantities are approaching a three orders of magnitude multiple of the total InP wafers fabricated in one year. However, a similar story was conveyed/disseminated by the GaAs industry at the end of the twentieth century with regards to silicon as the incumbent. It mainly took a disruptive battery technology change and one major cellular phone Original Equipment Manufacturer (OEM) buy in to enable GaAs as a replacement for silicon. A similar scenario is currently occurring opening a window of opportunity for InP. The advantages and performance of InP devices at Xindum Technologies will be explored as suited for the commercial wireless power amplifier industry. In the 1990s the cellular portable manufacturers were happy with silicon. It was a low cost material with acceptable performance. These were the days of mainly analog FM phones with GSM starting to appear. The batteries were 5 cells of nickel cadmium (NiCd) that have a cell voltage between 1.2-1.6 V. End of life for the five cell battery pack was 5 × 1.2 = 6 V. This was fine for silicon, but with the emergence of digital schemes and the demand for longer talk time, battery technology was refined. There is also a memory effect with the NiCd batteries that requires reconditioning by deeply discharging the battery and fully recharging a number of times. Typically, the NiCd batteries were rendered useless after a few hundred or thousand charging cycles. The two technologies that emerged as replacements were nickel metal hydride (NiMH) and lithium ion (Li Ion) with fuel cells and zinc air losing favor. The NiMH was advantageous as almost a direct replacement of NiCd with its cell voltages of 1.2 to 1.5 V. It enjoyed the advantage of no memory effect like NiCd. However, the …