NOTE C – PATENTS

The Company’s intangible assets at September 30, 2023 include patents with estimated remaining economic useful lives ranging from 10 to 16 years. For all periods presented, all of the Company’s patents were subject to amortization. The gross carrying amounts and accumulated amortization related to acquired intangible assets as of September 30, 2023 and December 31, 2022 were as follows:

Amortization expense for the three months ended September 30, 2023 and 2022 was $71,000 and $82,000, respectively. Amortization expense for the nine months ended September 30, 2023 and 2022 was $236,000 and $233,000, respectively. Future amortization of intangible assets for the next five fiscal years and thereafter is as follows:

One patent within the Cox Patent Portfolio expires in November 2023, and the balance of the patents within such portfolio have expired. The expiration dates of patents within the Company’s M2M/IoT Patent Portfolio range from September 2033 to May 2034. The expiration dates within the Company’s HFT Patent Portfolio range from October 2039 to November 2039. All of the patents within the Company’s Mirror Worlds Patent Portfolio and the Remote Power Patent have expired.