drupal 7, render array link.

rdashboards.module

  $form['full_calendar_link'] = array(
    '#type' => 'link',
    '#title' => '<i class="fa fa-calendar fa-2x"></i>',
    '#href' => 'fc/student-reports/calendar',
    '#options' => array(
      'html' => TRUE,
      'query' => array('assignee' => 'All'),
      'attributes' => array(
        'title' => t('Full calendar'),
        'class' => array('ctools-use-modal'),
      )
    ),
  );