Note 4. Revenue Recognition from Contracts with Customers

Disaggregation of Revenue

The Company's primary revenue streams include foundry fabrication services and product sales.

Foundry Fabrication Services

Foundry fabrication services revenue includes microelectromechanical systems ("MEMS") foundry services and Non-Recurring Engineering ("NRE"). Under these contracts, products are delivered to the customer at the completion of the service which represents satisfaction of the performance obligation as well as transfer of title. Depending on language with regards to enforceable right to payment for performance completed to date, related revenue will either be recognized over time or at a point in time.

Product Sales

Product sales revenue consists of sales of RF filters and amps which are sold with contract terms stating that title passes, and the customer takes control, at the time of shipment. Revenue is then recognized when the devices are shipped, and the performance obligation has been satisfied. If devices are sold under contract terms that specify that the customer does not take ownership until the goods are received, revenue is recognized when the customer receives the goods.

The following table summarizes the revenues of the Company's reportable segments for the three months ended December 31, 2019 (in thousands):

The following table summarizes the revenues of the Company's reportable segments for the six months ended December 31, 2019 (in thousands):

The following table summarizes the revenues of the Company's reportable segments for the three months ended December 31, 2018 (in thousands):

The following table summarizes the revenues of the Company's reportable segments for the six months ended December 31, 2018 (in thousands):

Performance Obligations

The Company has determined that contracts for product sales revenue and foundry fabrication services revenue involve one performance obligation, which is delivery of the final product.

Contract Balances

The Company records a receivable when the title for goods has transferred. Generally, all sales are contract sales (with either an underlying contract or purchase order), resulting in all receivables being contract receivables. When invoicing occurs prior to revenue recognition a contract liability is recorded (as deferred revenue on the Condensed Consolidated Balance Sheet).

The following table summarizes the changes in the opening and closing balances of the Company's contract asset and liability for the six months ended December 31, 2019 and 2018 (in thousands):

The amount of revenue recognized in the six months ended December 31, 2019 that was included in the opening contract liability balance was $5 thousand that related to filter sales. The amount of revenue recognized in the six months ended December 31, 2018 that was included in the opening contract liability balance was $28 thousand that related to non-recurring engineering sales and $25 thousand that related to MEMS business.

Contract assets are recorded when revenue recognized exceeds the amount invoiced. The difference between the opening and closing balances of the Company's contract assets and contract liabilities primarily results from the timing difference between the Company's performance and the customer's payment. The amount of contract assets invoiced in the six months ended December 31, 2019 that was included in the opening contract asset balance was $117 thousand which primarily related to MEMS business.

Backlog of Remaining Customer Performance Obligations

Revenue expected to be recognized and recorded as sales during this fiscal year from the backlog of performance obligations that are unsatisfied (or partially unsatisfied) was $0.5 million at December 31, 2019.

Grant Revenue

From time to time the Company applies for grants from various government bodies (state & federal), such as the National Science Foundation ("NSF"), to support research and development. In addition, the Company is eligible for "matching awards" from state boards to provide additional funds to the Company to supplement the funds awarded under the federal grant program. The Company records grant revenue as a part of revenue from operations given that grant revenue is viewed as an ongoing function of its intended operations. The revenue from grants is not viewed as "incidental" or "peripheral" which would result in the presentation of grant revenue as "Other income". The Company recognizes nonrefundable grant revenue when the performance obligations have been met, application has been submitted and approval is reasonably assured.