End Google Ads 201810 - BS.net 01 --> i work with sms and i want to convert my string to binary

this string is
encoded using the 16-bit UCS-2 character encoding

how i can do that;

i try code like comming and it not work

byte[] utf8Bytes = System.Text.Encoding.UTF8.GetBytes(s_unicode);
byte[] utf = System.Text.Encoding.Unicode.GetBytes(s_unicode);
byte[] utf1 = System.Text.Encoding.BigEndianUnicode.GetBytes(s_unicode);