You can use the connectionInfo parameter to specify connection encoding, e.g.:
<?php
$connectionInfo = [
'CharacterSet' => 'UTF-8',
];
$conn = sqlsrv_connect($serverName, $connectionInfo);
?>
Beware though that only two options exist:
- SQLSRV_ENC_CHAR (constant) for ANSI, which is the default
- 'UTF-8' (string) for Unicode