Exhibit A

JOINT FILING AGREEMENT

The undersigned hereby agree that the foregoing statement on Schedule 13G is filed on behalf of each of the undersigned in accordance with the provisions of Rule 13d-1(k) under the Securities Exchange Act of 1934, as amended, and that all subsequent amendments to this statement on Schedule 13G may be filed on behalf of each of the undersigned without the necessity of filing additional joint filing agreements.

Date: August 6, 2020

ADVANTEST AMERICA, INC.
By:	/s/ Keith Hardwick
	Name: Keith Hardwick
	Title: Chief Financial Officer
ADVANTEST CORPORATION
By:	/s/ Douglas Lefever
	Name: Douglas Lefever
	Title: Director, Managing Executive Officer